Here is the archive of the lists Lorendiac posts here, and here is his latest!- BC.
Ant-Man, Aurora, Black Widow, Blink, Electro, Gladiator, Jolt, Karma, Magneto, Mysterio, Professor X, Speed Demon, The Vulture, The Wasp, Yellowjacket . . . "obviously" they are all Marvel characters, right?
Argent, Blockbuster, Hitman, Huntress, Impulse, Manhunter, Psimon, Ravager, Raven, Spoiler . . . "obviously" they are all DCU characters, right?
Burnout, Freefall, Rainmaker, Voodoo, Zealot . . . "obviously" they are all Wildstorm characters who were created before Wildstorm became a division of DC, right?
Icon, Rocket, Static . . . "obviously" they are all Milestone characters, soon to be integrated into the regular continuity of the DCU, right?
Well . . . yes and no. The truth is: All of the "aliases" I just mentioned have been used on both the Marvel and the DC sides of the fence, for different characters!
Recently I saw someone on DC's own discussion forums asking for advice. He wanted to write and post a fanfic featuring what I gathered was an original character, but the heroic alias he had in mind was one which he realized DC has already used from time to time (not for anyone who ever had his own title, though). The fan wanted advice on whether he'd get in trouble for copyright infringement if he stuck with the name he wanted to use.
I figured he didn't really need to worry. First, because nobody can copyright a name all by itself; second, because DC doesn't even visibly object to the existence of thousands of online fanfics that obviously are using their distinctive characters (instead of just recycling the occasional name); and third, because if frequently swiping colorful names for their new characters from old characters at Marvel is good enough for DC (and vice versa), then swiping names from both companies certainly ought to be good enough for us common folk!
When I was a kid, I used to wonder how the various writers at DC and Marvel managed to keep coming up with nifty new "superhero names" or "supervillain names" that nobody had ever thought to use before. Now I know better. They don't necessarily sweat blood in the effort to come up with new aliases in the superhero genre! Often, they just dust off and recycle old names, from their own company's past continuity or a rival's, if they figure they can get away with it!
When I started soliciting suggestions for the first draft of this list, I could think of a few names offhand ("Captain Marvel" was an easy one), and I figured there were more I wasn't immediately remembering, and probably others used by characters I'd never heard of. I estimated I might end up with 30 "shared aliases" after my fellow fans had weighed in.
Live and learn! A week later, thanks to the help I received, my First Draft actually listed 166. Several months later, incorporating new suggestions from other people along with others I had dug up on my own, I had 303 in the Second Draft. Posting them stirred up a new wave of suggestions from alert readers, and in the year since then I've naturally made additional notes for future use whenever I stumbled across another case in my reading. Also: A few months ago the news came that the Milestone characters from the mid-90s were going to be integrated into the main DCU, and I decided that meant I could start counting Milestone characters as DC characters, regardless of what the legal technicalities of ownership may be at the moment. (Same statement applies to the Archie heroes whom DC had previously used in its Impact! Line and now has permission to integrate into regular DCU continuity.)
Also: I didn't spend much time worrying about Marvel's "New Universe" characters when I was working on the First and Second Drafts last year, but I've now corrected that, and found numerous matches to add to the list.
The upshot is that this Draft has 416 "aliases" which both Marvel and DC have used for characters (or someone else used them at another company, and then Marvel or DC later added those characters to their collections, one way or another). If I ever break the 500 mark, I'll release another Draft someday.
Ground Rules
1. I'm not interested in characters who have been around so long that they are in the "public domain." For instance, DC and Marvel have both put their own spins on various characters from Norse Mythology, Graeco-Roman Mythology, Egyptian Mythology, etc. And they've both done stories featuring names from Arthurian Legend. But they didn't "create" any of those characters, really, so I'm not interesting in calling those cases of "duplication." (On the other hand, I made a possible exception for personifications of the concept of "Death" at both companies. I don't see that the Marvel version or the Neil Gaiman version from "Sandman" were simply swiped from any single preexisting mythology.)
2. I am willing to list any character names that both companies have swiped from mythological sources and then recycled for "new" character concepts who definitely are not "the original Andromeda of Greek Myth" or whatever. (Both DC and Marvel have, in fact, used the name "Andromeda" for female heroes.)
3. I also ignore any cases where both companies have handled the same "licensed" characters at different times. Both DC and Marvel have published comics set in the "Star Trek" universe, for instance, but neither company ever claimed to have "created" the key characters.
4. "Group names" don't count unless individual members also demonstrate the habit of using that name or an obvious variation for themselves personally (as when a new member of the Green Lantern Corps starts calling himself "Green Lantern" as his heroic alias). Examples of what I don't count: DC has had evil organizations with the names "Cyclops" and "Colossus," but I don't count those as "duplicates" of the names of famous X-Men. Likewise, Marvel and DC each own characters who have used the name "Thunderbolt," but my entry for that alias does not mention Marvel's team concept known as "the Thunderbolts," because each member of the team has used some other colorful alias for himself or herself.
5. After looking at the examples of "Dr. Doome" and "Dr. Doom," I decided that "pronunciation trumps spelling." If two names are obviously meant to be pronounced exactly the same way by English-speaking readers, then I'll count them as "duplicate aliases" even if there are differences in how they are usually spelled and punctuated.
6. It appears that at least a few dozen members of Marvel's group "The Elements of Doom" have been mentioned by name in the group's published appearances. I believe it's also been stated in dialogue that they include members named after the full periodic table, not just those members whose names have been used in word balloons. So I'm assuming that any DC character named after a real chemical element has a a namesake at Marvel. In cases where it doesn't appear that such a character was ever mentioned by name at Marvel, I say "presumably one of the Elements of Doom" in the listing.
7. To keep the project down to a manageable size, I'm only counting characters who are controlled by Marvel or DC; either because they were created at those companies or because they were created at some other company whose "character stable" later ended up under the thumb of Marvel or DC. Any other, completely independent company gets ignored. For instance: Marvel and DC have both used the alias "the Ghost" for one supervillain apiece. I list those villains below, but I don't include any mention of Dark Horse's vigilante heroine "Ghost," because she is not the property of either DC or Marvel. Similarly, I ignored the Milestone and Impact characters last year, but I've changed my mind now that DC has permission to integrate both sets into its standard continuity and see what happens. And I've decided to include a couple of cases of costumed characters from Alan Moore's "Watchmen" who shared aliases with Marvel characters, although I've heard a rumor to the effect that Alan Moore will regain full control of those characters if and when DC lets the trade paperback collection go out of print. (Hey, it could happen! It's only been a couple of decades, after all!)
8. I ignore any characters who have only appeared in other media, such as TV shows, movies, regular novels, or games which adapted character concepts now controlled by DC or Marvel. However: If such characters later appeared in printed comic books, then that makes them fair game!
9. Defining the meaning of "alias" in this context has led me to some tricky decisions. I'm not interested in finding cases where both Marvel and DC have used such bland names as "John Smith" or "Mary Jones," whether those were "aliases" or "real names" of the fictional characters in question. On the other hand, I tend to include the more colorful names of Inhumans, Deviants, New Gods, and Metal Men (among others), even in cases where we are either told or led to believe that the exotic names being used may be the only names those characters have ever had. I suppose in some cases I'm settling for names that "look like a carefully chosen alias" even if they might not be.
10. Here are a few things I deliberately exclude from my list: "Atari Force" characters, because I don't think DC owns them and (as far as I know) they were never really integrated into the DCU. "Masters of the Universe" characters, for much the same reasons, although I know Superman did travel to Eternia and meet He-Man at least twice in the early 1980s. Amalgam characters, because they were not just "Marvel" or "DC," but deliberately swiping and merging elements of various characters owned by both companies.
11. Some Doubtful Cases: I am currently working on the theory that the characters known as "Comet the Super-Horse" (Silver Age Superman continuity), "Neon the Unknown" (Golden Age hero), "Omega the Unknown" (1970s hero), and "Deathstroke the Terminator" (Slade Wilson) all use those complete strings as their preferred aliases; not just the first words of each string. Thus, none of those guys are mentioned below in listings for "Comet," "Neon," etc. I don't list Tryco Slatterus under "Champion," either, because I believe that for millennia his full preferred "alias" was "Champion of the Universe."
Now, on to the main event!
THE MASTER LIST
Be warned: I don't make any claim to tell you everything you could possibly need to know about any of these characters. Most of the time, I won't even mention what their superpowers are (if any). Nor will I usually tell you exactly what issue showed a certain character using a certain alias for the first time. And I usually don't bother mentioning which company used that alias first. I always mention DC characters first, but only because "DC" precedes "Marvel" alphabetically! I provide as much data as I happen to feel the burning urge to provide in any given case, and you're welcome to do further research on your own time!
Acrobat
DC: Two users; both villains. One was a WWII-era villain who fought Judomaster and Tiger in the Charlton comics. One was a member of Amos Fortune's "Luck League" in one JLA story.
Marvel: At least three users (one lived in the 19th Century and fought the Rawhide Kid).
Agent Axis
DC: Golden Age Nazi villain who fought the Boy Commandos; later reappeared in "modern times."
Marvel: A WWII-era villain, retconned in during the 70s, who was somehow a merger of three Axis spies (one German, one Italian, one Japanese) into a single entity with the strength of three men.
Aluminum
DC: One of the second (and evil) team of Metal Men. Destroyed.
Marvel: Presumably one of the Elements of Doom.
The Anarchist
DC: Simon Ellis, villain who fought the JLA in the 1970s. (Just once, apparently?)
Marvel: Tike Alicar, hero, member of X-Statix; dead.
Anarchy/Anarky
DC: "Anarky" is Lonnie Machin, an anarchist vigilante who thinks he's a hero, but Batman and other superheroes generally disagree with him.
Marvel: "Anarchy" is a villain; a redheaded woman who worked for Flag-Smasher's ULTIMATUM outfit during the "Acts of Vengeance" event in 1989 (and hasn't been heard from since).
Andromeda
DC: In the Post-COIE era, and again after the Post-Zero Hour Legion Reboot, she was Laurel Gand, a retconned substitute for the role previously filled by the Pre-Crisis Supergirl in the continuity of the "Legion of Super-Heroes." She was erased by the 2004 Reboot of Legion continuity.
Marvel: An Atlantean superheroine.
Angel
DC: name for the heroine of the "Angel and the Ape" duo.
Marvel: Founding member of the X-Men; later "Archangel." (Also a Golden Age hero "The Angel" who was later retconned to have been two brothers taking turns. The Angel who married Beak may or may not qualify, since that was actually her real first name and I'm not sure if she ever tried to use it as an "alias.")
Anomaly
DC: Super-powered clone of Floyd Barstow; villain, but with some signs of scruples.
Marvel: A metaphysical being.
Ant-Man
DC: Jumbo Carson, villain (initially masquerading as a hero), who appeared in a single Batman story.
Marvel: Hank Pym's first heroic costumed identity.
Ape
DC: Sam Simeon is called "The Ape" in the titles of the series and various miniseries that have featured him working with Angel.
Marvel: One of the Morlocks.
Arclight
DC: Noah Pasternetti, villain.
Marvel: Phillippa Sontag, villain; one of the Marauders who performed the Morlock Massacre.
Argent
DC: Toni Moretti, heroine; one of the new batch of "Teen Titans" who debuted in the mid-90s.
Marvel: Samantha Hassard, a member of Clan Destine.
Argus
DC: Two users. One was an obscure villain; one is Nick Kelly, hero.
Marvel: Villain who cut off Leiko Wu's hand.
Ariel
DC: Temporary "Dial H for Hero" identity of Vicki Grant.
Marvel: Several users, including Kitty Pryde at one point.
Arsenal
DC: Three users. The first two were villains. The third was Roy Harper, hero; formerly "Speedy" and later known as "Red Arrow."
Marvel: An android long since destroyed. Also: a villain who fought Moon Knight.
Astra
DC: Hero; member of the Xenobrood.
Marvel: Several, including a member of the Shi'ar Imperial Guard and another who claimed to be a former member of Magneto's Brotherhood of Evil Mutants.
Atlas
DC: An action hero of ancient times.
Marvel: Steve Rand, villain. Later: Erik Josten, who's tried to be a hero as a Thunderbolt (after being a villain under other names).
Atom Smasher/Atom-Smasher
DC: "Atom Smasher," alias once used by Manfred Mota, Golden Age villain. "Atom-Smasher," alias used by Albert Rothstein (formerly "Nuklon" of Infinity Inc.)
Marvel: Two villains, brothers; Ronald English (dead) and then Michael English. They both used the hyphen.
Aura
DC: Heroine; one of the Ravers.
Marvel: Annie Herd, bounty hunter. Apparently last seen hospitalized with severe injuries.
Aurora
DC: One of the Recombatants who once fought the Titans; dead.
Marvel: Jeanne-Marie Beaubier, heroine; founding member of Alpha Flight.
Ballistic/Ballistik
DC: "Ballistic" was Kelvin Mao, hero; member of Blood Pack; dead.
Marvel: "Ballistik" is a Marvel UK character; member of something called "the Zoo."
Banshee
DC: Max Bine, a villain who fought the Question (Vic Sage) when he was still a Charlton character.
Marvel: Sean Cassidy, hero.
Barium
DC: Robot; member of an evil "Metal Men" team. Destroyed.
Marvel: One of the Elements of Doom.
Barracuda
DC: At least two.
Marvel: At least three.
Barrage
DC: Karnowsky, a Superman villain.
Marvel: One of the "Riders of the Storm" who worked for Apocalypse.
Basilisk
DC: Irish Autumns, hero. (A shameless parody of Scott Summers - Cyclops of the X-Men-in an old Inferior Five story.)
Marvel: Villain, dead.
Battleax/Battleaxe
DC: "Battleax" is an alias for Princess Norka of Nekrome.
Marvel: "Battleaxe" has been used by several people.
Beautiful Dreamer
DC: One of the Forever People.
Marvel: One of the Morlocks.
Bedlam
DC: Two of them. One was a villain who gave Young Justice a hard time.
Marvel: Four of them, apparently.
Bella Donna/Belladonna
DC: "Bella Donna" has been used twice. Once an obscure villainess; once a Yuppie Demon (whatever that is).
Marvel: "Belladonna" is Narda Ravonna, villainess. (I don't count Gambit's ex-wife because "Bella Donna" really was part of the name on her birth certificate; not an alias-although I had to check it just now to make sure.)
Black Death
DC: Villain who fought the JLA a few years ago.
Marvel: Two users; both villains.
Black Racer
DC: Supernatural entity who skis around collecting souls of dying people.
Marvel: Villain; member of the Serpent Society.
Black Widow
DC: A woman named Princess Hellene, listed in online resources as "Black Widow," once fought the Golden Age Flash and then died.
Marvel: At least three; the best-known (although not the first) is Natasha Romanoff.
Blacksmith/Blaquesmith
DC: "Blacksmith" is Amunet Black, a Flash villain.
Marvel: "Blaquesmith" was one of Cable's mentors in the alternate future timeline where he grew up. A second character later impersonated the first "Blaquesmith."
Blackwing
DC: Charlie Bullock, rookie superhero in the Gotham City of the Pre-COIE Earth-2; a shameless imitator of the Golden Age Batman.
Marvel: Two users; both villains.
Blindspot
DC: Mercenary whose suit lets him turn invisible.
Marvel: At least two.
Blink
DC: Temporary "Dial H for Hero" identity of Craig.
Marvel: Clarice Ferguson of the Exiles.
Bliss
DC: Nicole Callahan, member of Wildstorm's DV8.
Marvel: One of the Morlocks.
Blizzard
DC: Temporary villainous "Dial H for Hero" identity of Lisa Davis, but only in Pre-Crisis continuity.
Marvel: Several, usually villains. The second, Donny Gill, has recently tried to turn over a new leaf with the Thunderbolts.
Blockbuster
DC: Mark Desmond, now dead. Then his brother Roland, a Nightwing villain for a long time, now also dead.
Marvel: At least three. The third was one of the Marauders; he participated in the Mutant Massacre and was killed by Thor.
Bloc/Blok
DC: "Blok," member of the Pre-Zero Hour Legion of Super-Heroes.
Marvel: "Bloc" - a mercenary. "Blok" - a villain working for Mister X.
Bloody Mary
DC: Villain; member of the Female Furies. Also: A Milestone character.
Marvel: Two of them; one is evidently the alias of one of the personalities inside Typhoid Mary's head.
Bolt
DC: Larry Bolatinsky, assassin.
Marvel: Chris Bradley, hero; dead.
Bombshell
DC: Amy Allen, villain; recently infiltrated the Teen Titans on behalf of Deathstroke the Terminator.
Marvel: Wendy Conrad, villain; used to be one of the Death-Throws. ("Bombshell" was also the alias of a heroine in the alternate timeline of "The Last Avengers Story.")
Bounty
DC: At least three. One was an evil entity who took control of Dawnstar in "Legion of Super-Heroes" continuity in the early 90s (this character was presumably erased from existence by the Post-Zero Hour Reboot of Legion continuity). One was a mercenary who fought Damage. The latest one was a character in the "Emperor Joker" story arc.
Marvel: Female mercenary who dated Ben Grimm for a bit in Chris Claremont's run on the FF.
Bowman/The Bowman
DC: Two users. One is a former superhero who is the father of White Feather, the archer member of the Inferior Five. The other was a member of the Justifiers in the alternate timeline which the Extremists came from (after they had slaughtered all the other inhabitants, including Bowman).
Marvel: At least two. One was apparently a reincarnation of Sir Lancelot; the other is a member of the HYDRA Super-Agents.
Brain/The Brain
DC: "The Brain" is a villain; leader of the Brotherhood of Evil.
Marvel: Several users.
Brainstorm
DC: Several users.
Marvel: Insane villain who was manipulated into thinking he was just venting some frustration while dreaming.
Brother Power
DC: I'm told that the title character (an animated mannequin) of the old series "Brother Power, the Geek" strongly preferred to just call himself "Brother Power" and resented it when other people kept calling him "the Geek."
Marvel: Achmed Korba, villain; fought Spider-Man in one story arc in the 70s; possibly died at the end of it.
Brute
DC: Several users; all pretty obscure, it seems.
Marvel: Several, including an evil analog of Reed Richards from a place called "The High Evolutionary's Counter-Earth."
Bull's Eye/Bulls-Eye/Bullseye
DC: "Bull's-Eye" was a villain who fought the Golden Age Green Arrow in the old Pre-COIE continuity.
Marvel: "Bulls-Eye" was a Hydra assassin who apparently got just one appearance; he killed Nick Fury (or seemed to) in "Nick Fury, Agent of SHIELD #15"-and then got killed himself by the end of that story. Later, the assasin "Bullseye" became a notorious Daredevil villain.
Special Note on the Above: A year ago there was some disagreement regarding just how the Hydra assassin wrote his name. ("Bull's Eye? Bull's-Eye? Something else?") A couple of sources assure me he used "Bulls-Eye" as his alias throughout that story, so that's what I'm going with until further notice. Near as I can tell, however, that issue has never been reprinted as part of any TPB, and I don't feel like coughing up the money to buy a 39-year-old comic book just to check on some punctuation in the dialogue, so it's awfully hard to be sure. Other online resources have that alias punctuated in various other ways-and a year ago, when I was researching the point, I found multiple instances online where people were offering that guy's only appearance for sale on their websites with such commentary as "The First Appearance of Bullseye the Assassin!" or words to that effect. Clearly they either mistakenly believed, or else desperately hoped their unsuspecting customers would mistakenly believe, that the assasin on the cover of that comic is the same guy as the "Bullseye" who has killed two of Daredevil's old girlfriends: Elektra Natchios and Karen Page.
Bulldozer
DC: At least three. Most famously, this was the military nickname of Horace Eustace Canfield Nichols, who served with Sergeant Rock in Easy Company during WWII.
Marvel: At least two; the more famous one is a villain, a regular member of the Wrecking Crew.
Bulletproof
DC: A Milestone character.
Marvel: A codename used by the late Nathaniel Briggs when he was acting as a member of "Sentinel Squad O*N*E."
Burnout
DC: Robert "Bobby" Lane of Wildstorm's original Gen13 lineup.
Marvel: Alias for two members of the Mutant Liberation Front in succession; both dead.
Bushmaster
DC: Bernal Rojas, hero, member of the Global Guardians; dead.
Marvel: Two brothers, both villains. John McIver (dead), followed by Quincy McIver (longtime member of the Serpent Society).
Cain/Kaine
DC: "Cain" is the working name of David Cain, high-priced assassin.
Marvel: "Kaine" is an evil Spider-Man clone.
Calcium
DC: One of the second (and evil) team of Metal Men. Destroyed.
Marvel: Presumably one of the Elements of Doom.
Capricorn
DC: Villain who fought Superman and Batman in a single story in the 1970s. He died at the end of that story, but they didn't realize that.
Marvel: Several villainous Capricorns have served with some version of the "Zodiac" team at different times.
Captain Marvel
DC: Billy Batson, until recently.
Marvel: Several users; the first was Mar-Vell of the Kree (now dead), and both a son and a daughter of Mar-Vell have subsequently used the name (and so have a few others).
Captain Strong
DC: Horatio Strong, a Silver Age knockoff of the "Popeye the Sailor Man" concept.
Marvel: Not a masked crimefighter; but he was a Golden Age action hero who got exactly one appearance in "Daring Mystery Comics #3" in 1940. Hasn't been heard from since.
Captain Tiger/Captain Tyger
DC: Pirate-themed villain who fought the original Teen Titans.
Marvel: "Captain Tyger" was a French nobleman in the 17th Century who had a career as a pirate for awhile.
Cat/The Cat
DC: "The Cat" was the first alias used by Selina Kyle (better known as Catwoman); at least in the Golden Age continuity.
Marvel: "The Cat" was a costumed identity for Greer Grant before her physical transformation into "Tigra." "Cat" or "The Cat" has also been used by several other beings at different times, including Shen Kuei, a martial artist whose abilities rival those of Shang-Chi.
Catalyst
DC: Villain; last seen working as an assassin for Vandal Savage.
Marvel: Villain; used to work for HYDRA.
Catapult
DC: Member of the demon-hunting group known as the Hell-Enders.
Marvel: Hero; member of the original "Exiles" team of the Ultraverse; died soon after he debuted.
Catman/Cat-Man
DC: "Catman" is Tom Blake, a longtime Batman villain, supposedly trying to redeem himself nowadays. I believe that he - or his Golden Age version, anyway - originally used the hyphen in the middle, but he's long since abandoned that.
Marvel: At least two villains using the name "Cat-Man" have served with versions of the Ani-Men. They both died.
Catseye
DC: Japanese villain who fought the Suicide Squad.
Marvel: One of Emma Frost's Hellions; dead.
Catwoman/Cat Woman
DC: "Catwoman" is Selina Kyle, sometimes a hero, sometimes a villain.
Marvel: "Cat Woman" was a Golden Age villain, leader of a gang of thieves, who fought Captain America and then died at the end of her first appearance.
Cauldron
DC: Two or three of them. One is an obscure Golden Age villain, possibly demonic, who fought Plastic Man a few times. The more recent user of the alias is a robot, originally designed at Project Cadmus, which was forced to fight Superman a couple of times in the 1990s. (I'm not clear on whether Superman's second fight with "Cauldron" was with the same robot after it was rebuilt, or with a new robot built from much the same design as the first.)
Marvel: A villain.
Chain Lightning
DC: Apparently this name has been used by both the Pre-COIE and Post-COIE versions of a female character with multiple personality disorder who sometimes fights Captain Marvel Jr.
Marvel: Two users, both obscure.
Chairman
DC: The masked leader of an evil organization known as The Council which clashed with Supergirl -- meaning Kara Zor-El, the Pre-COIE version -- in the early 80s. I have no idea whether Chairman, and/or The Council, are still around in modern continuity.
Marvel: There was a Chairman who was a villain in an old Hostess Twinkies ad in the comic books. (It occurs to me that I have no idea whether those old Hostess ads are presumed to be "in continuity" or not.) There was also a Chairman in the 2099 timeline; a villain who was in command of the Ratpack.
Chameleon
DC: The alias used by the Post-Zero Hour rebooted version of the "Legion of Super-Heroes" character originally known as "Chameleon Boy."
Marvel: The first supervillain Spider-Man ever fought.
Champion
DC: According to DCUguide.com, there have been at least three users. They are allegedly Shazam, M'onel, and Herakles when he was masquerading as a run-of-the-mill modern superhero (I choose to mention Herakles to be complete; since he's a mythological figure in the public domain, I could just ignore him).
Marvel: Another alias used by a Wolverine villain also known as "Mister X."
Changeling
DC: Garfield Logan when he isn't calling himself "Beast Boy" instead.
Marvel: The former villain who died while impersonating Professor X (at the Prof's request).
Cheetah
DC: At least three. I think they've all been Wonder Woman villains.
Marvel: Esteban Carracus, villain; dead.
Chimera
DC: Several users.
Marvel: Several users. One was a Deviant Skrull who died in the "Marvel: The Lost Generation" mini.
Claw/Klaw
DC: Several users of "Claw."
Marvel: "Klaw" (Ulysses Klaw) is a villain.
Cloud
DC: "The Cloud" was a temporary "Dial H for Hero" identity of Mark.
Marvel: "Cloud" was a Defender in the mid-1980s.
The Clown
DC: Lyle Corley, a Flash villain; dead.
Marvel: One of these has served in the Ringmaster's Circus of Crime. Another was a member of the Crazy Gang in the 1980s (and maybe he still is, for all I know).
Cobalt/Kobalt
DC: "Cobalt" was a robot, a member of the third "Metal Men" team; eventually went rogue and was destroyed. "Kobalt" is a Milestone character.
Marvel: "Cobalt" is one of the Elements of Doom
Cobra/Kobra
DC: "Kobra" is Jeffrey Franklin Burr, villain.
Marvel: Previous alias of Klaus Voorhees, a villain who later called himself "King Cobra."
Coil
DC: Milestone character who fought Static in the 1990s.
Marvel: Villain; one of the Twisted Sisters in Shadow City.
The Collector
DC: Silver Age villain who fought a Batman/Hawkman teamup, and hasn't been heard from since.
Marvel: One of the Elders of the Universe. I'm told there was also a human thief who used this alias when he appeared in "Wolverine/Doop #1" (which I'd never even heard of).
Comet/The Comet)
DC: "Comet" was an "Earth-Born Angel of Love" in Peter David's "Supergirl" title. I've also been told that the Silver Age hero previously known as "Captain Comet" later started using just plain "Comet" as an alias. And Rob Connors, "The Comet," was an Archie character who apparently will soon be integrated into the DCU.
Marvel: "The Comet" was Harris Moore, created in the 1970s as a superhero with a retconned career from the 1950s; now dead.
Computo
DC: A villainous artificial intelligence who fought the Legion of Super-Heroes in their original continuity. Also: Danielle Foccart, a heroine, later swiped the name for herself (still in the original continuity before the Post-Zero Hour Reboot).
Marvel: An artificial intelligence created by Quasimodo.
Confessor
DC: There was a Confessor who worked for Brother Blood in the 1980s, and the name has been used consecutively by two heroes in "Kurt Busiek's Astro City."
Marvel: Russian mercenary who fought Maverick.
Controller
DC: Villain who fought Adrian Chase when he was The Vigilante with his own title in the mid-1980s.
Marvel: Basil Sandhurst, villain.
Copperhead
DC: Villain; real name unknown.
Marvel: At least three villains.
Copycat
DC: Gem Antonelli; member of Wildstorm's DV8.
Marvel: Vanessa Carlysle, villain, dead.
Crackerjack
DC: A hero in "Kurt Busiek's Astro City."
Marvel: A villain who appeared in the "Ghost Rider 2099" series.
Creeper/The Creeper
DC: Jack Ryder, hero, has intermittently appeared in stories as "The Creeper," going back about 40 years now. I am told that a Vertigo miniseries a few years seemed to retcon in a "previous" Creeper, a woman named Madeline Benoir, active in the 1920s. There was also a Creeper in the "DC One Million" event, living in the year 85,271.
Marvel: "Creeper" was the alias used by a kid living in New York City a century ago; a super-powered member of a group known as the Street Arabs. He was killed in the same "Runaways" story arc in which he debuted.
Crimson
DC: Jodi Slayton, heroine, daughter of Backlash. She worked with Wildstorm's Wildcore team for awhile, and later changed her alias to Jet.
Marvel: Villainess; member of a quasi-vampiric group called the Ravens; died fighting X-Factor.
The Crooked Man
DC: "The Crooked Man" was J.J. Crook, a crimelord who appeared in the "Chain Gang War" series and apparently died at the end of it (but I hear the body was never found after the big explosion).
Marvel: "The Crooked Man" was a crimelord who fought The Shroud.
Crossbones
DC: Nicholas Jones, member of Wildstorm's Wetworks, dead.
Marvel: Brock Lumlow, villain.
Crusader
DC: Two, both heroes. First: Don Powers, hero, apparently appeared in a single issue of "Aquaman" in the 1970s. Second: Derek Bradbourne, who appeared in one story in the early 90s and also seems to have faded into obscurity.
Marvel: Several users.
Crusher
DC: A villain who was once defeated by Bobo Bennetti.
Marvel: Several users.
Cyclone/Psyclone (please assume all users spell it "Cyclone" unless otherwise stated)
DC: At least four. One was originally a Quality hero in the Golden Age. One was briefly a villain, fighting the JLA in a single story in the 1970s. One was a temporary "Dial H for Hero" villainous identity of Nylor Truggs - retcon-erased by COIE. One is Maxine Hunkel, heroine; a granddaughter of Ma Hunkel, the Golden Age "Red Tornado."
Marvel: There have been at least three users of "Cyclone," all villains; the first one is dead. There is also a "Psyclone" in the 2099 timeline.
Cypher
DC: Three users; including Cameron Begay, formerly "Cypher" of the DEO and now better known as "Omni" of the "Relative Heroes."
Marvel: Doug Ramsey of the New Mutants, long dead.
Dark Angel
DC: A Wonder Woman villain.
Marvel: Several users.
Dark Rider
DC: Two of them, both villains; the second claims to have killed the first.
Marvel: Several of them; one was an evil Reed Richards of an alternate timeline.
Darkstar
DC: Any member of the Darkstars, an intergalactic outfit that tried to replace the (then-defunct) Green Lantern Corps at one point.
Marvel: Laynia Petrovna, currently dead.
Darwin
DC: A Tarzan parody who worked with the Inferior Five.
Marvel: A long-lost former X-Man.
Deadline
DC: Mercenary villain.
Marvel: Kishi Oramosha, villain.
Deadman
DC: Boston Brand, ghostly hero.
Marvel: "The Deadman" is apparently another alias used by a magical entity who appeared in "Wolverine: Evilution" and who also likes to modestly call himself "The Saviour."
Deadzone
DC: Jay Daniels, member of the S.T.A.R. Corps.
Marvel: John DeZoan, vigilante who killed members of organized crime outfits.
Death
DC: One of the Endless.
Marvel: the sister of Eternity; the entity whom Thanos is traditionally so obsessed with. Also the alias of various Horsemen of Apocalypse (including Archangel and Wolverine at different times).
Deathwish
DC: A Milestone character.
Marvel: An Ultraverse villain.
The Demon
DC: Etrigan is frequently just called "The Demon."
Marvel: Several users; first one was a human magic-user, real name unknown, who fought Thor in the mid-60s.
Destiny
DC: One of the Endless.
Marvel: Paul Destine, villain, dead. Irene Adler, villain and later part of Freedom Force (if there's a difference?), dead.
Dinah Soar/Dyna-Soar
DC: "Dyna-Soar" was a temporary "Dial H for Hero" identity of Lori Morning in post-Zero Hour "Legion of Super-Heroes" continuity.
Marvel: "Dinah Soar" was a founding member of the Great Lakes Avengers; now dead.
Disruptor/The Disruptor
DC: Two of them; the first one preferred "The Disruptor"; I'm not sure about the second. First: Michael Beldon, villain; son of "Brains" Beldon, criminal mastermind. Second: Angelica, a teenage villain (member of the Terror Titans) who was recently established as Michael's daughter. (I really didn't think he was old enough to have a teenage daughter, but what do I know?)
Marvel: At least two "Disruptors"; both villains; one of them is dead.
Doctor Death
DC: Dr. Karl Hellfern, a Batman villain.
Marvel: Thomas Bradley, became a villain serving the Axis in the WWII era; apparently this alias and bad behavior was a retcon imposed in modern times upon a Golden Age crimefighting character previously known as "Doctor Nemesis."
Doctor Doom/Doctor Doome
DC: "Dr. Doome" was an adversary of the original Seven Soldiers of Victory in the Golden Age.
Marvel: "Doctor Doom" (Victor Von Doom) is a villain.
Dog/Dogg
DC: "Dogg" is a Milestone character.
Marvel: At least two characters have used "Dog" as an alias.
Dominus
DC: Villain who's given Superman some bad times.
Marvel: Alien computer that became a supervillain.
Dragonfly
DC: Temporary "Dial H for Hero" identity of Chris King.
Marvel: Several users.
Dynamite/Dyna-Mite
DC: Apparently the word "Dynamite" alone has sometimes been used as an alias by the Golden Age crimefighter also known as "Dan the Dyna-Mite."
Marvel: "Dynamite" is Michael Crawley, a member of Psi-Force in the New Universe. "Dyna-Mite" was a British WWII-era crimefighter, member of a group called the Crusaders, according to a retcon in Marvel's "Invaders" series in the 1970s.
Echo
DC: Several users; one of them is the partner of Query; those two have served as the Riddler's henchwomen on various occasions.
Marvel: Maya Lopez; served as "Ronin" in the "New Avengers" team for awhile.
The Eel
DC: Mort Coolidge, villain.
Marvel: At least three of them.
Electro
DC: A "light ray creature" who was actually a hoax contrived by the Silver Age Lex Luthor.
Marvel: Several users; most famous is Maxwell Dillon, one of the earliest Spider-Man villains.
The Enchantress
DC: Member of the Shadowpact.
Marvel: Amora of Asgard, usually a Thor villain.
Enforcer/The N-Forcer
DC: Two different "Enforcers" fought Firestorm in the 1980s. Also: "The N-Forcer" is a hero in the Honor Guard in the universe of "Kurt Busiek's Astro City." (I'm not clear on the details, but some think there have actually been several different people inside the armored suits over the decades.)
Marvel: "The Enforcer" was a villain who was killed by one of the "Scourge of the Underworld" characters.
Fade
DC: A Milestone character.
Marvel: A mercenary in the timeline of Marvel's "2099" books.
Falcon
DC: Villain who fought the Silver Age Hawkman.
Marvel: Sam Wilson, hero; Captain America's co-star for several years in the 1970s.
Fang
DC: Jake Ketchum, werewolf and superhero; member of the band "Scare Tactics."
Marvel: Several users; at least two have been members of the Shi'ar Imperial Guard.
Fastball
DC: Obscure villain.
Marvel: Timothy Ferris; hero in the New Universe.
Fever
DC: Shyleen Lao, heroine; member of a previous version of the Doom Patrol.
Marvel: A cyberspace character in the 2099 timeline.
Firebird
DC: Serafina Arkadin, Russian superhero.
Marvel: Bonita Juarez, hero.
Firebrand
DC: At least four users. Most recently: Andre Twist, introduced in "Crisis Aftermath: The Battle for Blüdhaven #1."
Marvel: Gary Gilbert, villain; dead.
Firefist
DC: Lyle Byrnes, villain. This alias was also used by a Khund who briefly served with the "Legion of Super-Heroes," shortly before their Post-Zero Hour Reboot.
Marvel: An alias of Rusty Collins. Also: a serial killer who fought Spider-Man once, using a flamethrower glove.
Firefly
DC: Two, both of them Batman villains at different times.
Marvel: Very short-lived villain; fought the Shroud and died.
Flashback
DC: A Milestone character; she was a member of the Blood Syndicate. Before that, there was a French villain by that name who fought Batman and the Pre-COIE Wonder Woman in a single issue of "Brave and the Bold" and never appeared again.
Marvel: Gardner Monroe, who has been part of Gamma Flight, Beta Flight, and Omega Flight at various times.
Flex
DC: One of several aliases used by Sturgis Butterfield, a member of the Hero Hotline group.
Marvel: Hero who served with Alpha Flight and Beta Flight, but lost his powers on M-Day.
The Fly
DC: An Archie hero.
Marvel: A Spider-Man villain.
Fog/Fogg
DC: "Fog" was a member of a "Night and Fog" duo which operated for the Axis in WWII (according to a retcon in "All-Star Squadron").
Marvel: "Fogg" was an assassin; part of the "Knight and Fogg" duo which fought Spider-Man.
Freefall
DC: Roxy Spaulding, hero; founding member of Wildstorm's first Gen13 team.
Marvel: At least two; one is a villain in the MC2 timeline.
Frog Man/Frog-Man
DC: Villain who fought the Inferior Five.
Marvel: At least two "Frog-Man" characters. One was Francois Le Blanc, a member of the Ani-Men, now dead. The other was Eugene Patilio, who wore his father's old costume in a heroic role a few times in "Marvel Team-Up" in the 1980s. (He was the son of the original Leap Frog, an old Daredevil villain.)
Frostbite
DC: Member of Wildstorm's DV8.
Marvel: Obscure mutant in a group called "the Chosen" who fought the X-Men 2099 group.
Fury
DC: At least two of them, mother and daughter. The daughter, Lyta Trevor, was a founding member of Infinity Inc. (Pre-COIE, Lyta was the daughter of the Earth-2, Golden Age Wonder Woman. But Post-COIE, the "previous" Fury, Helena Kosmatos, was created out of thin air and retconned in as a 1940s heroine who had later become Lyta's biological mother.)
Marvel: "The Fury" is an almost unstoppable artificially created entity who specializes in killing superhumans.
Fusion
DC: Soviet operative who fought the Outsiders and died in the late 80s. Later: Temporary "Dial H for Hero" identity of Jay.
Marvel: Two different Spider-Man villains have used the name.
Gallium
DC: Robot member of the third "Metal Men" team; eventually went rogue and was destroyed.
Marvel: Presumably one of the Elements of Doom.
Gargoyle
DC: Bromwell Stikk, an old Titans foe.
Marvel: Isaac Christians; served as a Defender. Previously, there was another "Gargoyle," a Soviet scientist who died in his first appearance.
Geist
DC: Member of the Blood Pack; hero. Also a Geist in Wilstorm's Wildcore team.
Marvel: A villain; a diehard Nazi who finally got killed by Magneto.
Ghost
DC: Alec Rois, villain.
Marvel: Villain, real name unknown.
Gladiator
DC: Temporary "Dial H for Hero" identity of Chris King.
Marvel: Several users, including Kallark, leader of the Shi'ar Imperial Guard.
Gog
DC: Superman villain.
Marvel: Several of them.
Gold
DC: One of the original Metal Men.
Marvel: One of the Elements of Doom.
Gorgon
DC: Two of them (not counting any mythological Gorgons in the DCU, such as the original Medusa). One was a villain, one of the Extremists-though it eventually turned out that the only one who appeared onstage while fighting the Justice League was actually a robot duplicate of the "original" Gorgon. The other Gorgon was one of "The Hybrid" who once fought the Titans; apparently died later in Roulette's fight club.
Marvel: One of the Inhumans. Also: Tomi Shishido, villain who fought Wolverine and died.
Grace
DC: Grace Choi, created by Judd Winick for his recent version of the Outsiders team.
Marvel: Several users.
Grandmaster
DC: Leader of the evil robotic Manhunters.
Marvel: The Elder of the Universe who is obsessed with playing games.
The Griffin/Gryphon
DC: Griffin Grey, developed superspeed and superstrength, said he wanted to be a hero but often acted like a villain; now dead.
Marvel: "The Griffin" is Johnny Horton, villain. "Gryphon" is Ekatarina Gryaznova, who fought X-Force.
Guardian
DC: Jim Harper, Golden Age hero, and later his modern-day clone.
Marvel: James MacDonald Hudson of Alpha Flight.
Gunhawk
DC: A Batman villain.
Marvel: At least one, maybe two, "Wild West" characters from the 19th Century.
Gunshot
DC: Villain; served as a member of "The New Extremists" and later in the Overmaster's second Cadre.
Marvel: A Genoshan Magistrate.
Half-Life/Halflife
DC: "Half-Life" was Byron Stark, member of the Ravers; now dead.
Marvel: "Halflife" is an extraterrestrial villain. "Half-Life" was Anthony Masterson, a villain who fought the Hulk a few times -- and may or may not have committed suicide; online resources contradict one other on the subject of whether he was "dead" or merely in a "coma" when last seen.
Hammer
DC: Member of the Russian superhero team "The People's Heroes."
Marvel: Several users.
Harbinger
DC: Lyla (no last name known?), who was the Monitor's assistant before and during Crisis on Infinite Earths.
Marvel: At least two. One was a servant of Apocalypse; now dead.
Hard Drive/Hardrive
DC: "Hard Drive" was the first team leader of the Young Heroes.
Marvel: "Hardrive" was a villain; a cyborg member of the Dark Riders.
Harpy
DC: Temporary villainous "Dial H for Hero" identity of Vicki Grant.
Marvel: At least two have used this alias, including Betty Ross (later married Bruce Banner) when she was briefly mutated into a villainous creature.
Harvest
DC: Supernatural vigilante villain who recently fought the Birds of Prey.
Marvel: Several users, including Chi Lo, one of the Young Gods.
Haven
DC: The name, apparently an alias, used by a kind-hearted hermit whom Batman met just once, in "Detective Comics #514." (Died at the end of the story.)
Marvel: Radha Dastoor, apparently a powerful mutant, now dead.
Hawk
DC: Hank Hall, Sasha Martens, and Holly Granger have all served as the "Hawk" half of one "Hawk & Dove" heroic duo or another, at various times.
Marvel: Several users, including one of Killraven's Freemen.
Hazard
DC: Two; both villains; no apparent connection between them. One is Rebecca Sharpe, former member of the Injustice Society. One is Manuel Cabral, a criminal mastermind who used to give Steel (John Henry Irons) a bad time.
Marvel: Carter Ryking, mutant villain. Lost his powers on M-Day.
Heat Wave/Heatwave
DC: Mick Rory, an old Flash villain (from the Barry Allen era) who sometimes reforms and then goes bad again.
Marvel: One of the Spaceknights; went rogue and died.
Hero
DC: Hero Cruz, has an H-Dial which he uses; has served with the Ravers and the Titans (apparently very briefly in the latter case).
Marvel: At least two users; in one case it was a temporary alias of the Forgotten One.
Hitman
DC: Hired killer Tommy Monaghan; possibly dead at the end of his series (I'm told it's rather unclear).
Marvel: Burt Kenyon; assassin who fought Spider-Man and the Punisher.
Holocaust
DC: Name used by a Milestone character who later switched to "Pyre" for awhile.
Marvel: Villain; son of Apocalypse from the "Age of Apocalypse" timeline.
Hood
DC: George Cross, costumed hero in England; met Batman during "Knightquest"; may not have appeared again?
Marvel: Several users.
Hotshot
DC: Billy Lefferts, member of the "Hero Hotline" service.
Marvel: At least three users.
Hunter
DC: Several, including Rip Hunter who sometimes just uses this name.
Marvel: Several.
Huntress
DC: Paula Brooks, Golden Age villain. Then Helena Wayne, Pre-Crisis Earth-2 hero. And now it's Helena Bertinelli, who's kinda-sorta a hero, on a good day.
Marvel: A codename used by Bobbi Morse before she became Mockingbird.
Hyena
DC: Two villains.
Marvel: Henry Mortonson, Golden Age villain who fought the original Human Torch.
The Ice Man/Iceman
DC: "The Ice Man" was a villain hired to fight the L.E.G.I.O.N.
Marvel: "Iceman" is Bobby Drake, founding member of the X-Men.
Icon
DC: A Milestone hero.
Marvel: A Wakandan villain. Also the name of a computer program modeled on one version of "Heather Hudson" in the "Exiles" title.
Impulse
DC: Two users. Best known as a former alias of Bart Allen, hero who later served as "Kid Flash" and then "Flash"; now dead. Also: Richard Kent Shakespeare, who served with the Legion of Super-Heroes before the Post-Zero Hour Reboot.
Marvel: Member of the Imperial Guard of the Shi'ar; now dead.
Indigo
DC: Two users. A female hero; a member of Sovereign Seven. Later: an feminine android who seemed to be a villain; then was allegedly reprogrammed and seemed to be a hero while serving with the Outsiders; then turned out to be a villain after all; Brainiac 8, in fact; the character is now dead.
Marvel: Patient in the Clinic in "D.P.7" (a New Universe title); dead.
Inertia
DC: Thaddeus Thawne, a clone of Bart Allen and a villain; recently became a member of the new "Titans East."
Marvel: A female character in the Squadron Supreme timeline who infiltrated that group on behalf of Kyle Richmond's "Redeemers" resistance group.
Inferno
DC: Used at least twice, in different versions of Legion of Super-Heroes continuity. Once as a new alias for Dirk Morgna (Sun Boy), Pre-Zero Hour. Once as the alias of a female character, real name unknown, in Post-Zero Hour continuity.
Marvel: Several of them.
Ion
DC: Alias used, off and on, by Kyle Rayner, hero. (I'm told that a recent retcon has said that "Ion" is actually a separate entity that's bonded, off and on, with Kyle Rayner.)
Marvel: Violetta Todd, villain.
Iridium
DC: Robot member of the third "Metal Men" team; eventually went rogue and was destroyed.
Marvel: One of the Elements of Doom.
Iron
DC: One of the original Metal Men.
Marvel: One of the Elements of Doom.
Iron Butterfly
DC: A Milestone character.
Marvel: Two users; women who were analogs from different timelines.
Jack O'Lantern
DC: At least three. The latest one is Liam McHugh.
Marvel: At least four, all of them villains.
The Jackal
DC: The crook who ordered Joseph Wilson's (the future Jericho's) throat to be cut - right before Deathstroke the Terminator killed the Jackal and his stooges. Joseph just barely survived his injury. Later, there was a terrorist called the Jackal who fought Superman.
Marvel: Miles Warren, villain.
Jackhammer
DC: Two villains have used this name. One fought the Pre-COIE Superman (so he may not exist in continuity now). The other was a member of the Demoltion Team.
Marvel: Villain.
Jaguar
DC: An Archie heroine.
Marvel: An obscure villain who was killed by a "Scourge" in the 1980s.
Javelin/Javelynne
DC: "Javelin" was a former Olympic athlete from Germany who became a villain; currently dead.
Marvel: Several users of "Javelin." There was also one "Javelynne" who fought Hawkeye.
Jester
DC: Chuck Lane, originally a Golden Age Quality hero. Later: Cord Dexter Lemoyne, member of Wildstorm's Wetworks.
Marvel: Jonathan Powers, villain.
Jinx
DC: East Indian sorceress, villain.
Marvel: Several users.
Jolt
DC: Carlotta Rivera, hero. One of the "Blasters" until she, like most of that group, went "missing in action" and (I gather) simply hasn't been heard from in a long time.
Marvel: Hallie Takahama, hero; the first honest person to join the original Thunderbolts in the 1990s (of course, at the time she assumed they were honest superheroes too).
Karma
DC: Wayne Hawkins, served with the Doom Patrol, later died.
Marvel: Xi'an Coy Manh, founding member of the original New Mutants.
Killshot
DC: Russian cyborg villain; he was part of the group of professional asssassins called "the Hangmen," all of whom are now dead.
Marvel: Assassin who fought Spider-Man.
King
DC: "King" Standish was a Golden Age masked crimefighter called "The King" (and later an agent of the OSS during WWII).
Marvel: Several users.
Kismet
DC: A cosmic entity; their equivalent of Marvel's "Eternity."
Marvel: An alias taken by the character previously known as "Her."
Knight/Night
DC: At least two "Knights." First: Percival Sheldrake, Earl of Wordenshire, the "Knight" of the first "Knight and Squire" duo that consciously imitated the Batman/Robin duo in a story published in 1950. Second: Cyril Sheldrake, son and successor of the first Knight (having previously served as his father's "Squire").
Marvel: One "Knight" was an assassin who was part of the "Knight and Fogg" partnership that fought Spider-Man. At least two other "Knights" have also existed (with no connection to "Knight and Fogg"). Marvel has also had at least two or three minor characters who sometimes used the name "Night."
Knockout
DC: Kay, villain, former member of the Female Furies of Apokolips.
Marvel: Elizabeth Rawson, villain, member of the Femme Fatales and the Femizons.
Lamprey
DC: Tayla Scott was a student at the Legion Academy, a thousand years in the future, in the Pre-Zero Hour version of "Legion of Super-Heroes" continuity.
Marvel: Villain in Mark Gruenwald's "Squadron Supreme"
Lead
DC: One of the original Metal Men.
Marvel: One of the Elements of Doom.
Lightmaster
DC: Temporary "Dial H for Hero" identity of Chris King.
Marvel: Edward Lansky, villain.
Lilith
DC: Heroine, occasional Titan, eventually started calling herself "Omen." She's currently dead (I think).
Marvel: Daughter of Count Dracula; villain.
Lionheart
DC: Richard Plante, a distant descendant of the old Plantagenet dynasty, who became a hero working for the British government during the "Bloodlines event" (and may not have been heard from since that time?).
Marvel: Two or three users.
Lion-Mane/Lionmane
DC: At least 2 users of "Lion-Mane" -- one was a man who fought Silver Age Hawkman; one was a woman who fought Hawkman, post-Zero Hour. Also, there was a "Lionmane" villain who fought the Earth-2 Huntress, Pre-COIE.
Marvel: "Lionmane" has been used as an alias by Lo Chien, an evil warlord.
Livewire/Live Wire
DC: "Live Wire" was the heroic alias used by Garth Ranzz in the Post-Zero Hour rebooted version of "Legion of Super-Heroes" continuity (Pre-Zero Hour, he was known as "Lightning Lad"). "Livewire" is Leslie Willis, a Superman villain.
Marvel: Villain; member of the Circus of Crime.
Lockup/Lock-Up
DC: "Lock-Up" is Lyle Bolton, villain.
Marvel: "Lockup" was a Brood Mutant who died fighting the X-Men.
Lord Chaos
DC: Son of Donna Troy and Terry Long in an alternate future timeline where he grew up to be a world-conquering tyrant.
Marvel: A cosmic entity.
Lynx
DC: Teenage villain who formerly worked for King Snake and often fought Robin. (She's already died, come back from the dead, and died again - I think she's still dead at the moment.)
Marvel: At least three.
Maestro/The Maestro
DC: I'm not sure of these details, but I've been told that at least four different villains with musical themes have called themselves "Maestro" or "The Maestro" at some point; two of those also were called "The Mad Maestro."
Marvel: An evil future version of the Hulk. The name was also used by "modern Hulk" when an evil personality took over his body at one point.
Magneto
DC: Two users. One was a temporary "Dial H for Hero" identity of Robby Reed. One is a villain; a member of "The Awesome Threesome" group which fought Aquaman in the Silver Age.
Marvel: The first villain the X-Men ever fought.
Magog
DC: Ruthless vigilante introduced in the possible future of "Kingdom Come."
Marvel: At least two. One was a demon who fought the Hulk once. One apparently lives in the Mojoverse.
Mammoth
DC: Baran Flinders, villain.
Marvel: At least four users.
Manhunter
DC: Lots and lots and lots of them.
Marvel: Bounty hunter who went after Kid Colt in the 19th Century.
Manikin/Mannikin
DC: "The Manikin," first name Miranda, was a Batman villain in a two-part story in 1981. Hasn't been heard from since?
Marvel: "Manikin" - Whitman Knapp, hero, trained in Canada's Beta Flight program; became a regular face in the original "Alpha Flight" series in the late 80s and 90s.
Mantis
DC: A New God from Apokolips.
Marvel: The Celestial Madonna.
Masquerade
DC: A Milestone character.
Marvel: Member of Elektra's Order who quickly got himself killed after he debuted.
Master Man
DC: Two of them. First: A Golden Age hero they acquired from Fawcett and allegedly have never used at all since they got him! Second: A Golden Age Quality character who was basically the evil equivalent of the hero Kid Eternity.
Marvel: A diehard Nazi villain.
Match
DC: A clone of the modern Superboy.
Marvel: Ben Hammil, a student at the Xavier Institute.
Megaton
DC: Temporary "Dial H for Hero" identity of the Pre-Crisis version of Pete Ross.
Marvel: Jules Carter, villain, dead.
Mercury
DC: One of the original Metal Men.
Marvel: Numerous users. One of the Elements of Doom. Also a superheroic alias used by Makkari the Eternal in the 1930s/1940s. And there were other users.
Merlin/Merlyn
DC: "Merlyn" is an archer villain who has tangled with Green Arrow. He was also on Zandia's Olympic Archery Team in the 2000 Summer Olympics. In addition, "Merlin" is a name Baron Winters uses for his leopard when conversing with it -- we never understand the leopard's responses, but Winters apparently does.
Marvel: Several characters have reportedly used the name "Merlin" at one time or another; whichever Merlin was actually King Arthur's court magician would be disqualified under my rules (public domain and all that), but the various imitators who are just "original Marvel characters swiping the name of a legendary figure" are each qualified for this list.
Midnight
DC: Dave Clark, a Golden Age Quality Comics hero later acquired by DC.
Marvel: Several users.
Mirage
DC: An obscure Batman villain. Later: Miriam Delgado, heroine.
Marvel: At least two. Desmond Charne, villain, dead. Also an alias of Danielle Moonstar, heroine.
Misfit
DC: Charlotte Gage-Radcliffe, hero; initially called herself "Batgirl" before settling for this name instead.
Marvel: Villain. A client of the Power Broker who ended up superhumanly strong but also looked deformed; became a member of the Night Shift.
Miss America
DC: A Golden Age heroine they acquired from Quality; Joan Dale, who later married Derek Trevor according to Post-COIE continuity.
Marvel: A Golden Age heroine named Madeline Joyce; later married the Golden Age Whizzer (Robert Frank). Now dead.
Mist/Myst
DC: A Golden Age Starman villain and his daughter Nash have both used the alias "The Mist" (or perhaps sometimes just "Mist.") There was also a "Myst" who was a member of the demon-hunting group called the Hell-Enders.
Marvel: Either the real name or the alias of a Valkyrie who is part-Faerie on her mother's side.
Mister Big
DC: Villain in the alternate future timeline of the original OMAC stories by Jack Kirby.
Marvel: Two; one was a bad guy in the 1930s; one was Frederick Foswell in his "Ultimate Universe" version (in the original Silver Age Spider-Man continuity, Frederick Foswell was once the crimelord known as "the Big Man").
Mister Mind
DC: Originally a Fawcett character; a telepathic green worm who fights Captain Marvel.
Marvel: Mercenary who fought Team America once.
Mister Muscle
DC: One of several aliases used by Sturgis Butterfield, a member of the Hero Hotline group.
Marvel: Villain who was working for the Mayhem Organization when he fought Team America (apparently his only appearance).
Mockingbird
DC: This alias has been used by at least three different people (including Lex Luthor) when each of them was directing the activities of a different incarnation of the "Secret Six" concept.
Marvel: Bobbi Morse, heroine, who married Hawkeye and later died.
Molecule Man
DC: Temporary "Dial H for Hero" identity of Chris King.
Marvel: Owen Reece, who started as a villain but improved himself. I'm not sure what he's up to now.
Murmur
DC: Two. One a demon; one a Flash villain.
Marvel: Three users.
Mysterio
DC: Alias briefly used by a Silver Age Superboy Robot disguised in bandages.
Marvel: Quentin Beck invented the role as a Spider-Man villain. At least two other villains have copied him.
Nemesis
DC: Several users.
Marvel: Three users. The latest one was Amelia Witherspoon, who served with Alpha Flight.
Neon
DC: Temporary "Dial H for Hero" identity of Chris King. Also: Celeste McCauley (aka Celeste Rockfish), who served with the Legion of Super-Heroes before the Post-Zero Hour Reboot.
Marvel: One of the Elements of Doom
Neptunium
DC: Apparently a robot connected with the Metal Men, who was seen in at least one panel in "Metal Men #8" in the 1960s. (I've seen an online scan of that one panel, with the robot's name printed across the back of its shoulders - beyond that, I know nothing for certain!)
Marvel: One of the Elements of Doom.
Network
DC: Several users; one was Taryn Haldane, member of Sovereign Seven; hero.
Marvel: Several users.
Neutron
DC: Nat Tryon, villain.
Marvel: Apparently the alias which is preferred by the character who is usually called "Munchkin" by his teammates in "New Genix."
Nighthawk
DC: A 19th Century Old West hero.
Marvel: Kyle Richmond; at least two analogs of him have played significant roles in Marvel continuity. One joined the Squadron Supreme in their timeline; one was a longtime member of the old Defenders in the main 616 timeline, after briefly serving with the Squadron Sinister and then reforming.
Nightrider/Night Rider
DC: "Nightrider" was named David, also known as Dagon, a vampiric member of "Team Titans" (apparently erased from history during Zero Hour).
Marvel: "Night Rider" was one of the aliases used by the 19th Century Wild West vigilante also known as Ghost Rider and Phantom Rider. Several other characters in the Old West may have also used this alias, as well as "Phantom Rider," at one time or another; the online resources I consulted aren't entirely clear.
Nightshade
DC: Eve Eden, a superheroine they acquired from Charlton.
Marvel: Tilda Johnson, villain.
Nightwind
DC: Berta Skye Haris was a student at the Legion Academy, and later a member of the Legion, in the Pre-Zero Hour version of "Legion of Super-Heroes" continuity
Marvel: Female ninja villain, member of "Rising Sons" -- lost her powers on M-Day.
Nocturn/Nocturne
DC: "Nocturn" was an alien hero who fought alongside Guy Gardner. Now dead.
Marvel: Several users of the name "Nocturne." Best-known is probably T.J. Wagner, one of the six original members of the Exiles team which was organized by the Timebroker; T.J. is the daughter of an alternate timeline's versions of Nightcrawler and the Scarlet Witch.
Nova
DC: An alias used by a depowered version of Clark Kent when he set up a new costumed identity in an Imaginary Story (or "alternate timeline") of the Silver Age. (Note: The character got a cameo in the "Infinite Crisis" miniseries.)
Marvel: Richard Rider, off and on, and the name may also have been used by an unknown number of other members of the Nova Corps at one time or another. Also: Frankie Raye, a Herald of Galactus.
Null
DC: Thief; partner of Void; fought Batman and Superman in the Pre-COIE continuity.
Marvel: Giant android designed to oppose Galactus.
Oblivion
DC: At least two; one was the dark side of Kyle Rayner, more or less.
Marvel: Cosmic entity.
Omega
DC: A robot created by Brainiac 5 while he was secretly controlled by Pulsar Stargrave. The robot fought the Legion of Super-Heroes (in their original continuity) and was soon destroyed.
Marvel: Several users.
Oracle
DC: At least two. The first was a cosmic entity who gave the JLA and JSA some guidance in rescuing the original Seven Soldiers of Victory in a 1972 story. The second is Barbara Gordon, formerly Batgirl I.
Marvel: Several users; I think the best-known is a female member of the Shi'ar Imperial Guard.
Orca/Orka
DC: Orca was Grace Balin, a Batman villain; now dead.
Marvel: Orka is a villain; a mutated renegade Atlantean.
Osmium
DC: Robot member of the third "Metal Men" team; eventually went rogue and was destroyed.
Marvel: Presumably one of the Elements of Doom.
Outlaw
DC: Two. One was Rick Wilson, Old West character, star of a series of "Outlaw" stories in the 1970s.
Marvel: At least three; one was a British vigilante who deliberately mimicked the Punisher.
Overmind
DC: An alias once used by Professor Emil Hamilton.
Marvel: Grom, last survivor of the planet Eyung.
Override
DC: Villain; leader of a group called The Mainframe.
Marvel: Greg Herd, villain.
Ozone
DC: Villain who fought Green Arrow in the 1980s.
Marvel: Character who wanted to be a hero but was rejected for membership in a group called O-Force in the "X-Statix" title. Hasn't been heard from since?
[b]Ozymandias[/b]
DC: Adrian Veidt, mass-murderer; a former superhero in the "Watchmen" graphic novel (he'd retired from that about a decade before the main action of the story).
Marvel: A servant of Apocalypse.
Paragon
DC: Villain who once fought the JLA.
Marvel: At least four users; one was the character later known as "Her" and then "Kismet."
Patriot/The Patriot
DC: Member of the Freedom Brigade, now retired from superheroing; father of Myron Victor (Myron grew up to be "Merryman," the leader of the Inferior Five).
Marvel: At least two heroes have used the name "Patriot." First: Jeff Mace, Golden Age hero who (according to retcons in the 1970s) also filled in as Captain America for awhile, around the late 1940s. Second: Elijah Bradley, member of the Young Avengers. (Note: I get the impression that Jeff Mace called himself "The Patriot" but Elijah just goes with "Patriot.")
Payback
DC: A Milestone character.
Marvel: A Punisher imitator in the 1990s.
Persuader
DC: At least three; the most famous was a regular villain in at least two versions of "Legion of Super-Heroes" continuity; a member of the Fearsome Five.
Marvel: A Spider-Man villain who died in his first appearance.
Phantasm
DC: Several, including Danny Chase (a deceased Titan) and the villain mentioned in the title of the comic book adaptation of the animated film "Batman: Mask of the Phantasm."
Marvel: Villain who once fought Paladin (and lost); apparently hasn't been heard from since?
Phobia
DC: Angela Hawkins III, villain; has served with the Brotherhood of Evil.
Marvel: Two. One is a demoness; one is an Inhuman in the era of the Guardians of the Galaxy.
Phoenix
DC: Codename of an agent of the OSS in WWII, as established in "G.I. Combat" in the 1980s.
Marvel: Several; the most famous is Jean Grey (and/or the Phoenix Force that sometimes impersonates her and sometimes merges with her).
Photon
DC: Temporary "Dial H for Hero" identity of Galen.
Marvel: Jason Dean, villain. Later: Monica Rambeau, heroine, now called "Pulsar." Also: Genis-Vell, now dead (I think).
Pilgrim/The Pilgrim
DC: "Pilgrim" was Maritza Blackbird, member of Wildstorm's Wetworks.
Marvel: "The Pilgrim" was Bob Hardin, villain; he had also been the hero "Atom Bob," a founding member of the Ultraverse team "The Strangers," before he went bad.
Piper/The Piper
DC: At least two. One was a former villain who died as soon as he appeared, in "Aztek #1." It also seems to be the alias now preferred by Hartley Rathaway, a reformed villain who used to fight Barry Allen as "the Pied Piper."
Marvel: At least two. One of the Morlocks (believed dead), and one of the Savage Land Mutates.
Pixie
DC: Temporary "Dial H for Hero" identity of Vicki Grant.
Marvel: Several users.
Plasma
DC: Temporary "Dial H for Hero" identity of Lori Morning in post-Zero Hour "Legion of Super-Heroes" continuity.
Marvel: Leila O'Toole, villain.
Platinum
DC: One of the original Metal Men.
Marvel: One of the Elements of Doom.
Plutonium
DC: One of the second (and evil) team of Metal Men. Destroyed.
Marvel: One of the Elements of Doom.
Powderkeg
DC: Villain who fought the JLA at least once? I know very little about him.
Marvel: Villain.
Power Broker
DC: A Pre-Crisis villain who supplied weapons to other villains.
Marvel: A villain who used to make a living by selling other people super-strength.
Power Fist/Powerfist
DC: "Powerfist" is a Milestone character who fought Static.
Marvel: "Power Fist" is the analog, in another timeline, of the character known as "Luke Cage" and "Power Man" in the main timeline of the regular continuity.
Power Man/Power-Man
DC: I've run across a reference to the idea that a "Power-Man" also known as "King of Outer Space" once proposed marriage to the Silver Age Lois Lane, but I'm not clear on the details. Silver Age Lois also had a dream sequence in which she was "Power Girl" and Clark Kent was the super-powered, but wimpy and ineffectual, "Power-Man." There was also a Silver Age story with a mysterious new hero named "Power Man" who turned out to be a Superman Robot in disguise. This was reflected in "Kingdom Come" with a "Power Man" character who was a Superman Robot with a new paint job; I'm not sure if the Silver Age story was still supposed to have "really happened" in the past of the "Kingdom Come" timeline or not, though; so that "Power Man" may or may not have been a different robotic character than the one from the Silver Age.
Marvel: At least two users of "Power Man." One was Erik Josten, using it as his original villainous alias, long before he became Atlas of the Thunderbolts. The second was Luke Cage, hero.
Powerhaus/Powerhouse
DC: "Powerhouse" was a temporary "Dial H for Hero" identity of Jerry Feldon. Another "Powerhouse" was a villain who fought the Inferior Five. Also, "Powerhaus" was a member of Wildstorm's "DV8."
Marvel: At least three users of "Powerhouse." One was Alex Power, one of the Power Pack; just one of several aliases he's used over the years.
Primus
DC: Original leader of the Omega Men.
Marvel: Artificial lifeform created by Arnim Zola.
Prism/Prysm
DC: "Prism," a temporary "Dial H for Hero" identity of Chris King. "Prysm" is Audrey Spears, heroine, one of a new group of "Teen Titans" introduced in the mid-90s.
Marvel: "Prism" was one of the Marauders; died in the Mutant Massacre.
Professor X
DC: Mad scientist who fought Plastic Man in "Plastic Man #1" (that's the series that came out in the 1960s).
Marvel: Charles Xavier, founder of the X-Men.
Prometheus
DC: Apparently two or three; the latest one is a villain who gave the JLA some bad times.
Marvel: Member of the Pantheon.
Proteus
DC: At least two, both villains.
Marvel: Kevin MacTaggart, villain, son of Moira MacTaggart. Reality-warping mutant, now dead.
Psimon
DC: Villain who has often worked with the Fearsome Five.
Marvel: Hero; worked with Warlock (the former New Mutant guy) in a "Warlock"
series several years ago.
Puma
DC: Jackson Jones, villain; dead.
Marvel: Thomas Fireheart, sometimes portrayed as a villain.
The Puppet Master
DC: At least two. First, a Golden Age Batman villain. Second, Jordan Weir, who later became known as "the Puppeteer."
Marvel: Phillip Masters, villain; stepfather of Alicia Masters.
Pyre/The Pyre
DC: "The Pyre" is apparently a character who appeared in "Martian Manhunter #1,000,000." There is also a Milestone character who prefers the name "Holocaust," but used "Pyre" for awhile.
Marvel: Several users.
Quicksilver
DC: A Golden Age hero, originally belonging to Quality Comics, and now better known as "Max Mercury."
Marvel: Pietro Maximoff, hero.
Radion
DC: A Legion of Super-Heroes reject during their Post-Zero Hour era.
Marvel: Henri Sorel, villain (later known as Ravager).
Rainmaker
DC: Sarah Rainmaker, hero; founding member of Wildstorm's first Gen13 team.
Marvel: Villain in the 2099 timeline; member of a group called the Free Radicals.
Rampage
DC: Kitty Faulkner, sometimes a hero, depending upon her ability to control her temper when in her super-strong form.
Marvel: Stuart Clarke, villain.
Ravager
DC: Several users, including two of Deathstroke the Terminator's kids at different times.
Marvel: Henri Sorel, villain.
Raven
DC: Heroine (usually); brought together the other members of "The New Teen Titans" when that title began in 1980.
Marvel: Several users; all seem pretty obscure.
Reaper
DC: Three Batman villains, at least two of whom are no longer in continuity.
Marvel: A character who was a villain when he worked with the Mutant Liberation Front, but later became a hero in the Ultraverse.
Red Dragon
DC: At least four users.
Marvel: At least three users.
Red Eye
DC: Red Eye was apparently a villain in "Blue Devil #19" in the 1980s. May never have appeared again?
Marvel: Alias of a Cyclops-analog in the mini "Avataars: Champions of the Realm."
Red Fox
DC: Apparently "The Red Fox" was the oiginal alias for the French superheroine (secretly two sisters taking turns in that role) who later preferred to use the alias "The Crimson Fox." Both sisters are now dead.
Marvel: A Chinese guerrilla fighter in the WWII era who worked with Captain Savage and his Leatherneck Raiders, and died in action.
Redwing
DC: Carrie Levine, heroine; member of the "Team Titans" until she (and most of her team) got erased from history by Zero Hour.
Marvel: Alias for Sam Wilson's pet falcon; the name has also been used by a couple of characters in alternate timelines.
Reflex
DC: Two users. Walter Thorsson, hero; member of Sovereign Seven. Devlin O'Ryan, hero; served with the Legion of Super-Heroes before the Post-Zero Hour Reboot.
Marvel: Hero; member of the First Line in "Marvel: The Lost Generation."
Ricochet
DC: Speedster villain who fought the third Hawkman.
Marvel: At least three. Alias used by Spider-Man; this role (name and costume) was later revived by Johnny Gallo of the Slingers. There was also an agent of Mister Sinister who used the name; he's dead now.
Ringmaster
DC: Villain who once fought a Flash.
Marvel: Villain with a hypnotic hat; used to lead the Circus of Crime.
Risk/Risque
DC: "Risk" was one of the first members of the new "Teen Titans" team that debuted in the mid-90s.
Marvel: "Risque" fought X-Force, but later became an ally; is now dead.
Rock
DC: Two users. One was a temporary "Dial H for Hero" identity of Vicki Grant. One is Micah Flint, a Superman villain.
Marvel: At least two villains.
Rocket
DC: Two female Milestone characters consecutively used this identity when functioning as Icon's sidekicks.
Marvel: Ultraverse character, partner of Blast.
The Roman
DC: Nickname of Carmine Falcone, a mob boss in Gotham City; apparently dead (if we pretend "The Long Halloween" was meant to be firmly in continuity - rumors say it was never meant that way when first published).
Marvel: A mob boss who gave Wolverine some trouble.
Roulette
DC: Two villains. The first was a woman who fought the original Mister Terrific way back when (according to modern retcons). The second Roulette is the granddaughter of the first (and apparently believes the first Mister Terrific was her grandfather, but she may be wrong?).
Marvel: Two of them. One was Jennifer Stavos, one of Emma Frost's original Hellions; dead.
Saber/Sabre
DC: "Saber" was an assassin who fought Adrian Chase when he was the Vigilante. "Sabre" was John Zero, a villain who fought the Swamp Thing.
Marvel: Several users of "Sabre."
Sabre-Tooth/Sabretooth
DC: "Sabre-Tooth" was the alias used by two villains, one male and one female, who each fought Barry Allen at different times and each died in action.
Marvel: Sabretooth is Victor Creed, villain; apparently dead?
Sandman
DC: Several characters, beginning with Wesley Dodds in the Golden Age.
Marvel: Flint Marko, one of the earliest Spider-Man villains.
Sapphire
DC: Candace Jean Gennaro, hero, an "associate" in the Power Company.
Marvel: A Marvel UK character; one of the trio known as the Wyrd Sisters.
Savior/Saviour
DC: "Saviour" is Ramsey Murdoch, a Superman villain.
Marvel: Several characters have used one spelling or the other.
Scalphunter
DC: Brian Savage, a 19th Century hero.
Marvel: John Greycrow, villain, one of the Marauders who performed the Morlock
Massacre.
Scanner
DC: Female alien hero in the Vanguard.
Marvel: Several users.
Scar
DC: Milestone character.
Marvel: Ultraverse villain.
Scarecrow
DC: Jonathan Crane, a Batman villain.
Marvel: Ebenezer Laughton, villain. Also: a mystical hero who later took the name of "The Straw Man" to avoid being confused with Ebenezer.
Sentinel
DC: Alan Scott for awhile, when he was not using the name Green Lantern.
Marvel: Any one of a zillion mutant-hunting robots that have been built over the years.
Seraph
DC: Chaim Lavon, Israeli hero; served with the Global Guardians.
Marvel: New Universe character also known as "Guardian Angel."
Shard/The Shard
DC: "The Shard" was a superhero during part of WWII, according to a retcon in 2001. He was a member of the group known as the Seven Shadows - he and five of his friends all died in the same event in 1944. This character was also known as The Luminary, for some reason.
Marvel: Two users of "Shard"; one of them is Bishop's sister, a hero.
Shift
DC: Hero, one of the Outsiders; initially thought to be Metamorpho; actually began as just a piece of him that developed independent sentience and all that jazz, with altered powers. (Long before he came along, in the Post-Zero Hour version of Legion of Super-Heroes continuity, there was also a "Shift" who was a hero in Wildfire's Legion in the 75th Century.)
Marvel: Clifton Joseph, hero; member of "Genetix."
Shifter
DC: Temporary "Dial H for Hero" identity of Nick Stevens.
Marvel: One of the aliases used by the member of the Shi'ar Imperial Guard also known as "Shapeshifter" and "Hobgoblin."
Shockwave
DC: Arnold Pruett, mercenary villain.
Marvel: Two users. Lancaster Sneed, villain. Kathy Ling, member of Psi-Force in the New Universe.
Shrike
DC: At least four users.
Marvel: At least three users.
Siren/Psiren
DC: "Siren" is a water-breathing ecoterrorist villain.
Marvel: Several "Sirens," including Jennifer Pearson from the Ultraverse. Marvel also has a woman called "Psiren," a Psi-Cop who ended up assisting Warlock (the former New Mutant Warlock, that is) in a series he had several years ago.
Silver
DC: Robot member of the third "Metal Men" team; eventually went rogue and was destroyed.
Marvel: One of the Elements of Doom. Also: A Chinese mutant who ended up in the Alpha Flight training program.
Scorpio/Skorpio
DC: "Skorpio" is Dennis Samuel Ellis, villain.
Marvel: Numerous villains have used the name "Scorpio."
Shark
DC: Three of them; the one with the most staying power is a mutated tiger shark who's fought Green Lantern and other heroes on various occasions.
Marvel: Two of them; one was a Golden Age villain.
Silhouette
DC: Obscure villain. Also: a deceased heroine who was part of the backstory in "Watchmen."
Marvel: At least three; one is a heroine who has served with the New Warriors.
Silver Dragon
DC: Mercenary villain who fought Primal Force.
Marvel: Alias used by Heather Rand (after she had already died) when she was magically forced to fight her son Daniel (Iron Fist).
Siphon/Syphon
DC: "Siphon" is a villain; a member of the Freak Show.
Marvel: Two users of "Syphon." One is Thomas Boyd, a Psi-Force character in the New Universe. One was a Warpy who met the Excalibur team at least once.
Slag/Slagg
DC: "Slag" is a Milestone character.
Marvel: One user of "Slagg" and several of "Slag."
Slash
DC: Two villains, each of whom may have gotten just one appearance.
Marvel: Two users, apparently both villains.
Slasher
DC: Several; including a hired assassin who fought the Titans in the early 80s and promptly got killed by Adrian Chase, who'd just become the new Vigilante.
Marvel: Several users.
Sledge
DC: Powerful but dumb character who died heroically.
Marvel: Two users.
Slipstream
DC: Temporary "Dial H for Hero" identity of Lori Morning in post-Zero Hour "Legion of Super-Heroes" continuity
Marvel: Cameron Davis, who served with the X-Treme X-Men for a bit.
Slither
DC: Jimmy Tilton, hero; member of the "Scare Tactics" band; dead.
Marvel: Aaron Solomon, villain.
Snowman
DC: A Batman villain; the half-breed offspring of a male Yeti and a human woman.
Marvel: A character who met the "Ultimate X-Men" - I don't know if he's good, bad, or what.
Sodium
DC: One of the second team of Metal Men (all evil).
Marvel: One of the Elements of Doom.
Solaar/Solarr
DC: "Solaar" is a member of the space-traveling team known as the Vanguard.
Marvel: "Solarr" was Silas King, villain; dead.
Spark
DC: Alias used by Alya Ranzz in the Post-Zero Hour Reboot Version of the Legion of Super-Heroes. (Pre-Zero Hour, she had used the names "Lightning Lass" and "Light Lass" at different times.)
Marvel: Villain; member of the Avant Guard.
Sparks/Sparx
DC: "Sparx" is a hero; served as a member of the Ravers.
Marvel: "Sparks" is a villain killed and resurrected by The Hand.
Sparrow
DC: Codename of an Allied spy who died during WWII; also apparently the army nickname of a soldier in Sergeant Rock's Easy Company during that war.
Marvel: Apparently at least three.
Spear
DC: Mercenary who fought the Titans in the early 1980s.
Marvel: Two; both villains.
Specter/Spectre
DC: "The Spectre" has been Jim Corrigan, Hal Jordan, and Crispus Allen.
Marvel: "Specter" was Dallas Gibson, a teenage mutant student in the second "New Mutants" series, who was depowered on M-Day.
Spectra
DC: Heroine; apparently a name used by the former "Halo" in some old "Outsiders" comics (which I own but haven't read yet).
Marvel: Selena Slate, who used to fight Sleepwalker but apparently wasn't such a bad person? (I'm going on hearsay.)
Speed Demon
DC: Two users. First: a villain who fought the Inferior Five. Second: Jerry McGee, a Flash villain who later reformed.
Marvel: At least two villains.
Spellbinder
DC: At least three; all fairly obscure.
Marvel: Erica Fortune, star of the "Spellbound" miniseries in the late 1980s; apparently languishing in obscurity since then.
The Sphinx
DC: Villain who fought Plastic Man in the 1960s.
Marvel: The name has been used by Anath-Na Mut and Meryet Karim, husband and wife, both incredibly powerful. When last seen, they had merged together and traveled back in time a few thousand years to try to get things right the second time around.
Spinner
DC: Villain who apparently fought Batman and Robin just once in the Silver Age.
Marvel: An extraterrestrial; apparently a hero and a member of the "Galactic Alliance of Spider-Man" (whatever that means).
Spider Girl/Spider-Girl
DC: "Spider Girl" was a supporting character in "Legion of Super-Heroes"-related comics both before and after the Zero Hour Reboot, but hasn't been heard from yet in the latest Rebooted Legion Continuity.
Marvel: "Spider-Girl" is May "Mayday" Parker, teenage daughter of Peter and Mary Jane, in the alternate future timeline of "MC2."
Spider Queen
DC: A villainess of the Golden Age. Also: an evil spirit that fought Animal Man.
Marvel: Sharon Kane (or Shannon Kane), who began as a Fox Features Syndicate heroine in the Golden Age; but was retconned into becoming an Axis agent for awhile during WWII, according to scripts by Roy Thomas in an "Invaders" miniseries in 1993.
Spiral
DC: A member of the demon-hunting group known as the Hell-Enders.
Marvel: At least two; the more famous one is a six-armed woman who often works for Mojo.
Spitfire
DC: At least two. First: Nickname of Tex Adams, a fighter pilot with the "Eagle Squadron" during WWII. Second: Joshua Terrill, first-born child and onetime sidekick of the Golden Age Ray, still about ten years old (when last seen?) because of time in suspended animation.
Marvel: Jacqueline Crichton, later Lady Falsworth, who was retconned into Marvel's Golden Age continuity in the "Invaders" title in the 1970s. Later, another Spitfire was a heroine in the New Universe.
Spoiler
DC: Stephanie Brown, who also served as the fourth Robin before dying in "War Games"-or so we thought until recently.
Marvel: Mercenary who fought Spider-Man. Also: A villain from "Spidey Super Stories."
Sponge/The Sponge
DC: Miklos, a character who appeared in one or more old "Challengers of the Unknown" stories, was apparently known as "Sponge-Man" and also as "The Sponge"; he died bravely. Later, a Milestone character used the name.
Marvel: "Sponge" was one of the Warpies; a mutated child who appeared in "Excalibur" way back when. I know almost nothing about her. There was also a "Sponge" in DP7 of the New Universe.
Spook/The Spook
DC: At least two. First: Val Kaliban, a Batman villain without true powers, but a master of using special effects to create the impression he's a ghost or other supernatural being; most of his appearances happened in the Pre-COIE era. Also: Another villain in a "Legends of the Dark Knight" story arc who also fought Batman; he may have been intended as a "Post-Crisis Reboot" of the same concept, but the original Spook (Kaliban) has since been worked into Grant Morrison's run on the Batman title (and apparently died in the same story in which he appeared there, but if he "comes back from the dead" it won't be the first time).
Marvel: At least three users.
Spore
DC: Constance Hollis, a Plant Elemental villain.
Marvel: A Deviant mutate who liked to absorb Eternals and - apparently - make himself immortal thereby.
Squid
DC: "The Squid" was a Batman villain who was killed by Killer Croc way back in 1983.
Marvel: Donny Callahan, a Spider-Man villain.
Squire
DC: Three people have been "Squire" at different times. The first and second (father and son) each later became "Knight."
Marvel: Superhero who died in the "Marvel: The Lost Generation" mini.
Stalker
DC: Fantasy character who briefly had his own series in the 70s; was later revealed in a retcon to have died in WWII.
Marvel: Several users.
Starlight
DC: At least two. The first is a Milestone character. The second is Natasha Irons, formerly the fourth hero to be known as Steel.
Marvel: Tania Belinsky, formerly a Red Guardian (she served as a Defender for awhile).
Static
DC: Virgil Ovid, a Milestone hero.
Marvel: At least three users.
Stealth
DC: Heroine; member of L.E.G.I.O.N.
Marvel: At least three.
Steamroller
DC: Villain.
Marvel: Member of the Unlimited Class Wrestling Federation. (That's all I know.)
Steel Hawk/Steelhawk
DC: "Steelhawk" is a superpowered mercenary.
Marvel: "Steel Hawk" is Arun Bakhti, a terrorist/mercenary/assassin.
Stinger
DC: Two villains.
Marvel: Several different users.
Stranglehold
DC: Female assassin who fought the Titans.
Marvel: Deviant; member of a group called "the Sword" that worked for the Damocles Foundation; fought X-Force; last seen being turned into a lizard?
Stretch
DC: Tom Longacre, retconned into the "Golden Age" continuity in the late 80s as a superheroic, Gingold-drinking predecessor of the Elongated Man. Ended up with "Hero Hotline."
Marvel: Member of the second Pride in "Runaways."
Strobe
DC: Villain who fought Ray Palmer.
Marvel: Villain; member of the Mutant Liberation Front
Strong Man/Strongman
DC: "Strongman" was a villain who fought the Justice League in the late 70s, as part of the evil "Luck League."
Marvel: At least two users of "Strong Man" and two users of "Strongman."
Stuntmaster
DC: Temporary "Dial H for Hero" identity of Chris King.
Marvel: George Smith, who's been a villain, a hero, and a TV actor.
Sublime
DC: Rachel Goldman, member of Wildstorm's DV8.
Marvel: Sentient bacteria; villain.
Sun Girl
DC: Villain in the current "Titans East" group.
Marvel: Mary Mitchell, superheroine in the Golden Age. Had her own title for three issues; then served as a new sidekick to the original Human Torch.
Sunspot
DC: Temporary "Dial H for Hero" identity of Vicki Grant.
Marvel: Roberto DaCosta, founding member of the original New Mutants.
Supernova
DC: Alias used by Booster Gold in the "52" series.
Marvel: Apparently another alias of Nova Omega (Garthan Saal), who is now dead.
Supreme One
DC: Villain who used to fight Aquaman.
Marvel: Leader of the Quists; boss of the alien known as Lucifer who originally crippled Professor X.
Sureshot
DC: Member of the demon-hunting group called the Hell-Enders.
Marvel: Two users. One is a female villain. One was an agent of the XSE in Bishop's native future timeline; that character died in action.
Swarm/The Swarm
DC: "The Swarm" is a Milestone villain.
Marvel: "Swarm" is Fritz von Meyer, diehard Nazi. His "body" is just a skeleton surrounded by zillions of mentally controlled bees; hence the name.
Swashbuckler
DC: Michael Carter, hero, based in Houston, Texas. Nephew of Greg Saunders, the cowboy-themed "Vigilante" who was a member of the original Seven Soldiers of Victory. Swashbuckler teamed up with Batman once in 1980, and has never been heard from since.
Marvel: An ally of Deathlok's in his native timeline.
Taboo/Taboo
DC: "Taboo" is Amanda Reed, Wildstorm heroine. There was also a "Tabu" who was a female mercenary; she fought Animal Man and later died.
Marvel: "Taboo" is a villain; stepfather of Topaz the sorceress.
Talon
DC: The trained falcon used by Bird (one of Bane's henchmen) before he died. More recently: A new hero who became a Teen Titan during the "one year gap" after Infinite Crisis.
Marvel: A former codename for "X-23."
Tarantula
DC: Two of them. Jonathan Law, Golden Age hero. Catalina Flores, using the name more recently, much less heroic.
Marvel: Several characters. The newest one is Maria Vasquez.
Tempest
DC: At least three: Temporary "Dial H for Hero" identity of Vicki Grant. Joshua Clay, Doom Patrol member, dead. Later the new alias of Garth (formerly "Aqualad").
Marvel: The alias previously used by the Shi'ar Imperial Guardsman later known as Flashfire. More recently, the name used by Nicolette Giroux of the Exemplars.
The Thinker
DC: At least four of them.
Marvel: The preferred alias of the brilliant villain usually called "The Mad Thinker."
Thorn/Thornn
DC: At least two "Thorns." First: Rose Canton, the Golden Age version of the "Rose and Thorn" concept, and the mother of Jade and Obsidian. Second: Rose Forrest, the more modern version of the "Rose and Thorn" concept.
Marvel: Multiple users; looks like at least two for each spelling variation; one "Thornn" was the sister of Feral of X-Force in the 1990s.
Thunderbolt
DC: Peter Cannon, who started as a Charlton character. Also, I believe the Golden Age Johnny Thunder's magical helper was frequently just called "Thunderbolt" and/or "T-Bolt." And in the 1980s Jonni Thunder was also called "Thunderbolt."
Marvel: William Carver, African-American speedster hero, now dead. Marvel also has another "Thunderbolt" speedster who only got one appearance in an old Hulk story; real name unknown.
Tigra
DC: Darkseid's ex-wife; mother of Orion.
Marvel: Greer Grant, heroine.
The Timekeeper
DC: Villain who fought the Zoo Crew in the early 1980s.
Marvel: Scientist who worked for AIM.
Tin
DC: One of the original Metal Men.
Marvel: Presumably one of the Elements of Doom.
Titania
DC: At least two. One was a villain in pre-Zero Hour "Legion of Super-Heroes" continuity. The other is the Faerie Queen who appeared in the "Books of Magic" stories and probably falls into the "public domain" exemption I listed above, but I'll mention her anyway.
Marvel: At least two. Davida DeVito, villain, dead. Mary "Skeeter" MacPherran, villain.
Topaz
DC: One of the Recombatants who fought the Titans and then died.
Marvel: Young sorceress heroine. Also: a Queen of Gwendor, member of Ultraforce, heroine, in the Ultraverse.
Torpedo
DC: . Villain; leader of "The Awesome Threesome" group which fought Aquaman in the Silver Age.
Marvel: At least three users.
Torque
DC: Dudley Soames, villain; dead.
Marvel: Several users; one is a villain, one of the Twisted Sisters in Shadow City.
Twilight
DC: A Milestone character, among others.
Marvel: At least two. One is a mutant in the "X-Nation 2099" series. Another Twilight was a member of the New Universe's DP7 group; apparently died in a battle with the Famileech.
Typhoon
DC: Two users; both villains.
Marvel: Two users; one is a villain; one is a detective who works as the partner of someone called "Cutlass."
Uranium
DC: Evil robot created by Doc Magnus before he created the Metal Men.
Marvel: One of the Elements of Doom.
Valor/Val-Or
DC: "Valor" is a heroic alias sometimes used by the character also known as Mon-El, Lar Gand, and M'Onel. (I have long since lost track of his more recent continuity, but I believe "Valor" was the alias he used when he had his own series in the early 90s -- I think that would be just before the Zero Hour reboot of everything relating to the Legion of Super-Heroes?)
Marvel: "Val-Or" is a mutant Moloid with telepathic abilities.
Vapor
DC: Carrie Donahue, hero. (www.dcuguide.com also has a vague mention of a second "Vapor," without providing any useful details.)
Marvel: Ann Darnell, villain; member of the U-Foes.
Venom/Venomm
DC: "Venom" was a villain who once fought the first Firestorm.
Marvel: Several users of "Venom" - the best-known is Eddie Brock when merged with an alien symbiote; he is (or they are) usually a villain. "Venomm" was Horatio Walters, who fought Black Panther and later switched sides.
Vixen
DC: Mari Jiwe McCabe, heroine.
Marvel: At least three of them (and that's not counting the ant whom Ant-Man I apparently named after one of Santa's reindeer?).
Void/The Void
DC: "Void," one of the original WildC.A.T.S. who came to DC when ABC/Wildstorm merged into them. Before that, there was a "Void" who was a thief, partnered with "Null," who fought Superman and Batman in the Pre-COIE era, and may not exist in modern continuity.
Marvel: "The Void" is the arch-enemy of the Sentry.
Volcana
DC: Apparently an inhabitant of Kandor in the 1990s who originally hailed from Apokolips.
Marvel: Marsha Rosenberg, Molecule Man's girlfriend for awhile in the 1980s.
Voodoo
DC: Priscilla Kitaen, one of the original WildC.A.T.S.
Marvel: Donny (last name unknown), a mutant member of a group called "the Children of Heaven"; he appeared in a single X-Factor story 19 years ago and hasn't been heard from since.
Vulcan/Vulcann
DC: "Vulcan" was a villain who fought the JSA in the 1970s.
Marvel: "Vulcan" is Gabriel Summers, villain; the recently-revealed long-lost "third Summers brother"; Cyclops and Havok being his siblings. Before we heard of him, the "X-Men 2099" series showed the heroes fighting a villain called "Vulcann."
Vulture
DC: Two, both villains.
Marvel: Many users; the most notorious is Adrian Toomes, one of the earliest villains to clash with Spider-Man.
Warbird/The War Bird
DC: "The War Bird" was Tom Sharp, heroic American aviator in WWII.
Marvel: "Warbird" is one of several aliases used by Carol Danvers over the years. There is also a "Warbird" in the 2099 timeline.
The Wasp
DC: 1940s villain who once fought the Golden Age, Quality Comics hero then known as "Quicksilver" (and now known as "Max Mercury").
Marvel: Janet Van Dyne, heroine.
Weasel
DC: Villain who fought Firestorm
Marvel: Several users.
White Dragon
DC: William Heller, villain.
Marvel: At least three users.
Whirlwind
DC: Villain who apparently got just one appearance and may have died at the end of it.
Marvel: David Cannon, villain.
Wildcat
DC: At least four; all heroes. Ted Grant, Golden Age hero, started the tradition and still uses the name sometimes; the latest user is his long-lost son; the other two Wildcats are dead.
Marvel: Codename or alias used by a guy who was a teammate of Logan's (Wolverine's) on "Team X" at some point many years in the past, before Logan got all that adamantium added to his skeleton.
Wildfire
DC: Carol Vance Martin, a Golden Age heroine from Quality Comics. Later: Drake Burroughs, hero, in at least two different versions of "Legion of Super-Heroes" continuity, Pre- and Post-Zero Hour.
Marvel: Harold Paprika, racist villain with a blowtorch.
Wild Thing
DC: An Earth Elemantal, created partially from the delirious mind of recently deceased ecoterrorist Alan Bolland; eventually destroyed by Swamp Thing.
Marvel: At least three users. An alias used by a character in DP7 in the New Universe. Later, a "Marvel UK" heroine in a short-lived series in the early 90s. Also: the daughter of Wolverine and Elektra in the alternate future timeline of MC2.
Windshear
DC: A Milestone character
Marvel: Colin Hume, hero; served with Alpha Flight; was depowered on M-Day.
Witch/Wytch
DC: "Wytch" was a Milestone character
Marvel: A few characters have gone by "Witch" or "The Witch" on occasion.
Witchfire
DC: Heroine; partner in the Power Company. (Initially thought she was Rebecca Carstairs, but was actually some sort of mystical duplicate of the "real" Rebecca.)
Marvel: A member of the Alpha/Beta/Gamma Flight programs in Canada.
The Wizard
DC: At least two. William I. Zard, Golden Age villain, who was recently absorbed into Ragman's rags. Also, a temporary villainous "Dial H for Hero" identity of Robby Reed.
Marvel: Bentley Whitman, villain.
Wonder Man/Wonder-Man
DC: "Wonder-Man" was a superhero in a single Silver Age story; it turned out his personality came from the mind of a Superman Robot (previously nicknamed "Ajax") after it had been transferred into a similarly strong, but more truly "living," android body; hence his new face was quite different from Superman's; sadly, he died at the end of the story.
Marvel: "Wonder Man" is Simon Williams, hero.
The Wrecker
DC: A Silver Age Batman villain. Also, a temporary "Dial H for Hero" identity of Jerry Feldon.
Marvel: Several of them; the most famous was Dirk Garthwaite, leader of the villainous Wrecking Gang.
Yellowjacket
DC: Reed Victor, former superhero, father of The Patriot, and thus grandfather of Merryman (of the Inferior Five)
Marvel: One of several aliases Hank Pym has used. Later: Rita DeMara, a female Yellowjacket who was a villain and then a hero; now dead.
Zealot
DC: Zannah of Khera, one of the first WildC.A.T.S.
Marvel: Thomas Moreau, a Genoshan mutate.
Zinc
DC: Robot member of the third "Metal Men" team; eventually went rogue and was destroyed.
Marvel: Presumably one of the Elements of Doom.
Zirconium
DC: One of the second (and evil) team of Metal Men. Destroyed.
Marvel: One of the Elements of Doom.
Zombie/Xombi
DC: "Zombie" was one of Bane's henchmen in "Knightfall." Also: It's been suggested that the Milestone character "Xombi" probably pronounced his alias exactly the same way as "Zombie," but wanted to have a more distinctive spelling; I don't know for sure if the X was meant to be pronounced as a Z.
Marvel: "The Zombie" was Simon William Garth, who was "undead" for awhile and is now just plain dead.
Closing Words
If you want to know more about any of the multiple users of a particular name in the Master List, good places to start looking are:
http://www.marvunapp.com/
and
http://www.dcuguide.com/
Beyond that, sometimes Wikipedia or other online resources will have useful data (although I believe many of the characters on this list are so obscure that Wikipedia is unlikely to have any pages about them).
And, of course, if you see anything I got wrong, or know of any examples of "shared aliases" which I am still missing, be sure to set me straight! That word "Draft" in the title is my way of acknowledging that anything this ambitious is always a work in progress, since I can't possibly know and remember everything about every DC or Marvel character who's ever been published! There's always more to learn!
For instance: As I write this, it's only been a couple of days since I discovered that Captain America, in one of his Golden Age adventures, fought a female villain who led a gang of thieves and called herself "Cat Woman." (She died in her first and only appearance in 1945, which helps to explain why I never heard of her before.) Who knows what other cases are still lurking beneath my radar?