Inventing a new comic book character is an interesting experience for a comic book creator. So long as the character was introduced after, say, Superman, there is always that slight chance that you might have just created the next, say, Superman. Then there are those characters that are introduced as jokes; fun ideas that are just thrown out there. It's when those ideas turn into hits that you truly realize the truth in what William Goldman famously says about Hollywood: "Nobody knows nothing."

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The following characters (listed chronologically in order of appearance) were invented as jokes or parodies and eventually grew into something much more. On the other hand, something like Sergio Aragones and Mark Evanier's excellent "Groo" is not on this list, as it began as a parody of Conan and, over 30 years later, continues on as a parody of Conan. These characters, however, ended up in a far different place than when they were jokingly introduced.

15 POPEYE

It's hard to imagine it now, but the comic strip where Popeye the Sailor Man debuted, "Thimble Theatre," was in its tenth year by the time that he debuted! The strip originally starred a thin woman named Olive Oyl and her boyfriend, Harold Hamgravy. Eventually, Olive's brother, Castor Oyl, joined the cast and the strip became about the misadventures of the three of them -- Olive, Hamgravy and Castor. Hamgravy was engaged to Olive, but he had a bit of a wandering eye. In a 1929 series of adventures, Castor and Ham wanted to get to Dice Island to find a famous casino. Castor had recently gotten a hold of a magical Whiffle Hen named Bernice who would give him great luck when he rubbed her head. They needed a boat and a captain. In stepped Popeye.

Popeye the Sailor Man was about as exaggerated of a sailor cliche as you could get, but he also had a certain sort of charm. When the storyline was finished, readers kept writing in asking for the writer and artist of the strip, Elzie Crisler (E.C.) Segar, to bring back Popeye. He did and very soon after, Popeye was the star of the strip, which became one of the most popular in the entire comic strip industry. It remains in syndication to this very day, although it was re-named "Popeye" officially during the 1970s.

14 SCROOGE MCDUCK

When we say "joke" characters, we don't always mean characters who are necessarily funny in their own right, but also characters who were exaggerated to the point of setting up a comedic plot. That was the point of Scrooge McDuck when he showed up in Dell Comics' "Four Color Comics" #178 at Christmastime in 1947. Legendary Walt Disney comic book artist Carl Barks created the character as a foil of Donald Duck and nephews Huey, Dewey and Louie.

An obvious play on the character Ebeneezer Scrooge from Charles Dickens' "A Christmas Carol," Scrooge McDuck was a miserly old man who was so bored on Christmas that he decided to ring up his nephew Donald and invite him (and his grandnephews) to Scrooge's cabin, mostly just to mess with him by tricking him into thinking he was being attacked by a bear. Instead, an actual bear comes into the cabin and Donald and the boys end up befriending the bear and bear cub. An impressed Scrooge invites them over for Christmas dinner. Barks then decided to use Scrooge as a foil again and then decided to make Scrooge slightly less of a jerk, which led to a series of amazing "Uncle Scrooge" stories that are among the most famous Barks ever wrote and drew.

13 SQUADRON SUPREME

squadron-supreme

As the 1970s began, both DC Comics and Marvel Comics were starting to employ a new generation of comic book writers, basically the first generations of comic book writers to have grown up reading comic books (unlike guys like Stan Lee and Gardner Fox, who were around when comic books first started). Roy Thomas was soon writing as many comics for Marvel as Stan Lee, and DC was slowly working in writers like Denny O'Neil and Mike Friedrich. Since these writers were all roughly around the same age, they were all friendly with each other.

That friendliness led to 1970's "Avengers" #85, which was a clever little crossover between Thomas' "Avengers" and O'Neil's "Justice League of America," where Thomas would introduce new villains called the Squadron Sinister that were based on the Justice League (Hyperion was Superman, Nighthawk was Batman, Doctor Spectrum was Green Lantern and the Whizzer was the Flash), while O'Neil did much less of a cross-over in "Justice League," instead having the League face evil doubles of themselves who just had the attributes of Avengers (like Hawkman fights evil Hawkman, who hits like an iron, man). Soon, new heroic versions of these characters were introduced as the Squadron Supreme, and they've been popular Marvel characters ever since!

12 HOWARD THE DUCK

Another one of those "new generation" comic book writers was Steve Gerber, who was given his first chance at an ongoing series at Marvel Comics with 1972's "Adventure into Fear," which starred the Man-Thing. Since the Man-Thing didn't talk or even really think, Gerber had to come up with a way to tell new stories, so he introduced the idea of the Nexus of all Realities being in Man-Thing's swamp, so alternate Earths all collide in that one spot. In "Adventure into Fear" #19, Steve Gerber, Val Mayerik and Sal Trapani were in the middle of an epic storyline that involved people showing up in the swamp from all different alternate Earths.

As a gag, one of the people who showed up on Earth wasn't a person at all, but Howard the Duck, a creature from an Earth that was populated by funny animals, like the Disney films or the "Looney Tunes" cartoons. He was there just as a gag, but the character amused Gerber, so he began to use him more and audiences responded. Soon, Howard got his own best-selling comic book series and became one of the most popular comic book characters of the 1970s, even getting his own newspaper comic strip (which was a really big deal at the time). Gerber and Marvel got into an ownership dispute over Howard, sadly, and Gerber quit Marvel.

11 FOOLKILLER

Before Gerber split from Marvel, he continued his Man-Thing stories from "Adventure into Fear" into a "Man-Thing" ongoing series. In 1974's "Man-Thing" #3, Gerber introduced Ross G. Everbest, an Evangelical Christian who was obsessed with the belief that all of the sinners out there were fools and he had to kill them all. He donned a flamboyant costume and armed himself with a "purification" gun, and would often warn people with a business card a day before killing them. It stated, this way: "Foolkiller / e pluribus unum / You have 24 hours to live. Use them to repent or be forever damned to the pits of hell where goeth all fools. Today is the last day of the rest of your life. Use it wisely or die a fool." Everbest died an issue after he debuted. It was just meant to be a brief parody of the lengths some people will go for their zealotry.

However, Gerber then brought the idea back in his next series, "Omega the Unknown," when a man named Greg Salinger took up the Foolkiller title. Gerber later invented a third Foolkiller, who briefly had his own title in the early 1990s. Currently, the Salinger Foolkiller has his own series at Marvel following appearances as part of Deadpool's "Mercs for Money."

10 ROCKET RACCOON

"Marvel Preview" was a black and white comic book magazine by Marvel that specialized in introducing new characters. The second issue introduced Dominic Fortune and the fourth issue introduced Star-Lord. That same issue, "Marvel Preview" #4, had a back-up story written by Bill Mantlo that introduced Prince Wayfinder, who was searching for the famed "Sword in the Star." Wayfinder appeared again in 1976's "Marvel Preview" #7, written by Mantlo and drawn by Keith Giffen. In that same issue, he encounters a talking raccoon named Rocky Raccoon. This was a reference to the Beatles' song of the same name.

Six years later, Mantlo brought the character back, re-naming him Rocket Raccoon and had him team-up with the Hulk in "Incredible Hulk" #271 (by Mantlo and Sal Buscema). The issue was an extended Beatles riff. Rocket was popular enough that Mantlo and a young Mike Mignola wrote an acclaimed miniseries starring Rocket and his friends. Then Rocket went into character limbo before he was brought back as part of what eventually became the Guardians of the Galaxy. Now he's one of Marvel's most famous characters!

9 CEREBUS

Cerebus is the first character on this list who actually debuted as an ongoing series. However, the Cerebus who debuted in 1977's "Cerebus" #1 barely resembled the Cerebus who we said goodbye to decades later in "Cerebus" #300 (Cerebus' creator, Dave Sim, said in 1979 that he would do exactly 300 issues of "Cerebus." At the time it seemed like a very bold claim, but that's precisely what he ended up doing). Originally, Cerebus was a parody of sword-and-sorcery comics in general and Conan the Barbarian specifically. The book starred a talking aardvark named Cerebus, who was also a barbarian.

While the series never stopped being a parody, the ideas being parodied and the tone of the book changed dramatically after the first couple of years. The first sign of that was the long story arc known as "High Society," which is just like it sounds: Cerebus having to adjust to being part of high society after being a barbarian for so long. This led to satirical stories about the nature of politics, which led into the even more nuanced "Church and State" story arc. The comic remained funny, but it was now an entirely different, much more thoughtful book than the initial basic parody it started as.

8 NEMESIS THE WARLOCK

When it comes to Nemesis the Warlock, the word "joke" might be a bit of a stretch, but we think it applies. In 1980, British comic creators Pat Mills and Kevin O'Neill came up with an idea for a new feature for the popular comic book anthology "2000 A.D." It was called "Comic Rock" and the idea was to tell a serialized story where each part was based on a different rock and roll song. It was essentially a challenge by Mills to see if he could do it. The first arc was called "Terror Tube," with the first chapter being based on the Jam's awesome hit song, "Going Underground."

A spaceship piloted by Nemesis was being chased through a series of tubes (hence "going underground"). The second part of the story was based on "Killer Watts," a then-current sampler album of "high voltage" rock songs. No one seemed to really be into the whole "rock" aspect of the story, but people liked Nemesis well enough, so even though the whole thing was meant as an experimental lark, they instead decided to say "screw it" and start up a new story starring Nemesis. The character proved popular and Mills wrote new Nemesis stories until the end of the decade (then, ten years later, brought the character back to wrap it all up in 1999).

7 CARRIE KELLEY

Carrie Kelley from The Dark Knight Returns as Robin

In 1982, brothers Gilbert, Jaime and Mario Hernandez launched "Love and Rockets," an anthology series featuring stories by each of them, but mostly from Gilbert and Jaime, who each told their own long-form serialized stories featuring their own unique characters. Jaime's most famous character was Maggie, who starred in his stories (her friend Hopey became a big part of the series, as well, but Maggie has always been the main character). Jaime would also do just fun little drawings that he would send in to the "Comics Journal" and they would publish them. One of them was of Maggie drawn like Robin in 1982.

A couple of years later, Frank Miller was working on the project that would become "The Dark Knight Returns." He was hanging out with fellow star artist John Byrne, when Byrne told him that since the story was set in the future, and thus Miller had some more freedom with the story, that he should make Robin be a girl. Byrne showed him the Hernandez drawing as an inspiration. Miller used it to inspire the creation of Carrie Kelley, the female Robin in "The Dark Knight Returns."

6 AMBUSH BUG

Ambush-Bug leaps across the cover of a DC cover from 1984 in Superman's suit

Comic book artist Keith Giffen was drawing a Superman/Doom Patrol team-up in 1982's "DC Comics Presents" #52, written by Paul Kupperberg, when Giffen offered up a new character to be the villain for the issue. The character was called Ambush Bug, and he would use miniature "bugs" to teleport himself to wherever the bugs would fly. He was intended to be a ridiculous villain, but it is worth noting that he actually murders a District Attorney in that issue, so you could tell that he was not intended to be someone with a big comedic future.

However, Giffen kept bringing him back as a villain until he decided to instead make Ambush Bug take a turn and decide he wanted to be a superhero. He had some more guest appearances in "Action Comics" by Giffen, where Ambush Bug kept trying to befriend Superman until he launched into a series of hit miniseries drawn and co-written by Giffen (along with Robert Loren Fleming).

5 LOBO

Just a few months after he created Ambush Bug, Giffen was at it again with a new creation he co-created with writer Roger Slifer in "Omega Men" #3. The year 1982 had seen the publication of the smash hit miniseries "Wolverine" by Chris Claremont and Frank Miller, which saw a huge spike in popularity for the violent mutant hero. Giffen and Slifer wanted to parody that brand of violent anti-hero in general, but make it Wolverine-specific, hence "Lobo," which is Spanish for wolf.

He showed up as a mercenary in the "Omega Men" story, but a few years later, Giffen brought him back for a "Justice League International" story; response to the character was overwhelming. He included him in the new "L.E.G.I.O.N." series he was launching with writer Alan Grant and soon Lobo was one of DC's most popular characters, with Giffen and Grant writing a number of hit "Lobo" miniseries before Grant then wrote a "Lobo" ongoing series, as well. The joke eventually faded into popularity and Lobo hasn't sustained an ongoing series in a number of years. However, due to his re-appearance in "Justice League vs. Suicide Squad," he appears due for a resurgence.

4 JOHN CONSTANTINE

Perhaps the weirdest joke of all of these characters, the character who became John Constantine, the most successful of all of the Vertigo-era of characters, started just as a sight gag by "Saga of the Swamp Thing" artists Stephen Bissette and John Totleben. They were both fans of the hit British pop group of the early 1980s, the Police, and its popular lead singer, Sting. So, in 1984's "Saga of the Swamp Thing" #25, they just drew Sting into a panel.

When the writer of the series, Alan Moore, asked his collaborators what they would like to see in the book, they told him a guy who looked like Sting. Moore was up to the challenge, but as he thought about it, he came up with a great angle on the character and in "Saga of the Swamp Thing" #37 (amusingly enough, drawn by a fill-in artist, Rick Veitch), John Constantine made his first official appearance (although #25 was retroactively deemed a Constantine appearance). He became Swamp Thing's sort of adviser in the ways of magic, but mostly he was a magical confidence man, using Swamp Thing to do what Constantine wanted to get done (luckily, Constantine's interests often coincided with the good of the world, as well).

3 TEENAGE MUTANT NINJA TURTLES

In 1984, Kevin Eastman and Peter Laird had been working with each other on a few different comic projects, but nothing serious. One night, while brainstorming ideas, they had what they felt was a hilarious one. They would self-publish a comic book that would make fun of four of the most popular comic books in the industry at the time, but mostly the work of the superstar artist Frank Miller. The books were "Daredevil" and "Ronin" by Miller, which both were part of the ninja craze; "New Mutants" from Marvel, which was about teenage mutants; and "Cerebus," which, as we saw earlier, was about a talking aardvark. Combining them all, they came up with the Teenage Mutant Ninja Turtles.

They printed a little over 3,000 copies and put an ad in the comic book trade publications. Much to their surprise, their idea really resonated with the public and the teen Turtles were a smash success! With the book now a legitimate comic book hit, Eastman and Laird promptly moved beyond the satirical angle of the original comic and just embraced the concept. After all, people apparently loved it, so why not lean in? The Turtles have gone on to become pop culture superstars in the decades since.

2 TICK

When Bed Edlund was a teenager in the mid-1980s, he was part of a group of friends that played role playing games and collected comic books. One of the characters he came up with during their role playing was the Tick. He then used the character as the superhero mascot of the comic book store that the group of friends attended, New England Comics. Edlund then got the chance to write some silly stories featuring the character in the store's newsletters.

The shop decided to get into publishing comics as well, and they ultimately decided to use Edlund's character as a comic book series. This was all while Edlund was still in college, mind you. "Tick" was a hilarious send-up of superheroes and it quickly became a critical success at the time. Less than a decade later, it was adapted into a successful and acclaimed cartoon series for Fox. New England Comics remains the publisher of "Tick" comics to this very day.

1 GWENPOOL

During the "Spider-Man" event "Spider-Verse," Marvel introduced alternate reality versions of Spider-Man. A few of them were featured in a miniseries that led into "Spider-Verse" dubbed "Edge of Spider-Verse," with each issue having a different creative team introducing a new Spider-Man riff. The second issue, by Jason Latour and Robbi Rodriguez, featured a reality where it was Gwen Stacy that gained the powers of Spider-Man and not Peter Parker. She became Spider-Woman, but fans referred to her as "Spider-Gwen." She was soon popular enough that she got her own ongoing series.

In 2015, Marvel decided to do a bit where they had various different comic book covers feature variant covers featuring variations of Gwen Stacy, like Gwen Stacy as Captain America, Gwen Stacy as Iron Man, etc. For the cover of "Deadpool's Secret Secret Wars" #2, Chris Bachalo drew Gwenpool, a combination of Gwen Stacy and Deadpool. Despite only being a funny cover drawing, the character became a hit with fans and Marvel soon did a Gwenpool back-up story in "Howard the Duck." She now has her own ongoing series.

What current "joke" character do you think has the best chance to become a star character? Let us know in the comments!