The CW’s continuously expanding Arrowverse hit the air in late 2012 with the inaugural season of Arrow. Since then, the Arrowverse has spawned three additional live-action shows: The Flash, Supergirl, and DC’s Legends of Tomorrow. And another will soon enter the family, as Kate Kane/Batwoman is getting a solo series of her own, starring Ruby Rose. With this many shows running concurrently and sharing the same universe, there exists an unfathomable amount of lore to keep track of. Characters, locations, backstories, and much more can all get lost or forgotten in the fray. This is especially true since each of the four series have so much going on at once. Drop time travel, the multiverse, and magic into the mix and the madness grows exponentially.

Again, there is a lot to keep up with. Every aspect of the Arrowverse bears a fascinating quality, yet characters and events come and go. Sometimes the coming and going happens with little fanfare, hence the need to acknowledge characters that many fans may have forgotten existed. There are heroes and villains that have not been seen in years, many of which disappeared after a show’s first or second season. Meanwhile, other characters feature in one of the series so infrequently that it is a surprise when they finally return. In the following list, such characters receive much deserved recognition. This includes heroes and villains that were once the cornerstone of certain Arrowverse shows, as well as those that were mere, but impactful, villain-of-the-week types.

20 BIZARRO

Bizarro Supergirl forgotten arrowverse characters

Bizarro Supergirl arrives in Supergirl’s pilot season, during the aptly titled “Bizarro” episode. Off the bat, she is compelling. Maxwell Lord essentially creates her, taking the near-gone body of a hospitalized patient and experimenting on her. Once Bizarro’s transformation into a Supergirl-like figure is complete, Lord sends her after Supergirl. Through brainwashing, he nearly succeeds in having Bizarro kill the Girl of Steel.

When last seen, Bizarro is being placed in a medically induced-coma by the DEO. Supergirl promises that to wake her up when the time is right. Unfortunately, it seems that time will not soon arrive. Bizarro hasn’t even garnered so much as a mention since season one. If her introduction into the series has slipped the minds of fans, it’s no wonder why.

19 JUSTICE SOCIETY OF AMERICA

Justice Society of America on Legends of Tomorrow

The end of Legends of Tomorrow season one teased a massive new addition to the Arrowverse in the Justice Society of America. For months after its premiere, Hourman’s appearance in that final episode garnered plenty of anticipation and interest with regards to what the second season would bring. Unfortunately, barring Amaya/Vixen, the JSA does not stick around for long.

Aside from a few cursory mentions thanks to Amaya, the older team of heroes is rarely brought up in conversation. Even during the team’s brief time on the show, they seldom have much to do. Thus, there aren’t many memorable moments that would place them on the forefront of the audience’s mind.

18 LINDA PARK

The Flash's Linda Park

Though she’s historically Wally West’s girlfriend, Linda Park debuts in The Flash season one as a love interest for Barry Allen. An intriguing addition to the cast, this version of Linda is a sports writer for Central City’s local newspaper. The dynamic between her and Barry, whereby she’s confident and his awkwardness instantly draws her in, remains one of the show’s most thrilling depictions of a romantic relationship. Their fleeting union leaves much to be desired, though.

Within just a few episodes, Linda ends their romance, citing Barry’s overly apparent love for Iris as the key issue. Since all has gone well for the WestAllen relationship, Linda’s dumping of the Speedster isn’t frowned upon. But it’d still be nice to see her return in some capacity.

17 HARLEY QUINN

Harley Quinn’s introduction during Arrow’s second season was immediately met with excitement. At the time, the Suicide Squad had already proved a perfect fit for the show. Therefore, Harley would only serve as the optimum way in which to elevate the stakes for that particular storyline. As the story goes, Suicide Squad’s live-action film of the same name prevented Arrow’s creative team from pursuing either the Task Force or Harley any further.

It’s no surprise, then, that the beloved character is now little more than a mere reminder of what could’ve been. Given all that has transpired since her brief appearance in season two, Harley’s being scarcely remembered also warrants little shock and awe.

16 RED TORNADO

Red Tornado on Supergirl

Now that Supergirl is entering its fourth run, Red Tornado seems but a blip on the Girl of Steel’s radar. She battled the robot early in the show’s first season, dispatching him in a single episode -- “Red Faced.” As a villain-of-the-week kind of foe, he receives no attention past that first season episode.

Not until an episode during the “Crisis on Earth-X” crossover, which takes place in Supergirl’s third season, does the character return. The version of him that appears, however, is an Earth-X iteration that’s more advanced than what Supergirl fought in National City. Considering Red Tornado evolves into a heroic figure in the comics and other cross-media representations, it’s unfortunate that he’s nothing more than a one-and-done Arrowverse foe.

15 CONNOR HAWKE

Connor Hawke in Star City 2046

On any other show, “Star City 2046” would be remembered as a series highlight for how wild it gets. Since Legends of Tomorrow’s wild side comes out in every episode, this particular hour of television remains a forgotten gem. During the episode, the Legends travel to a dystopian future. The Green Arrow has retired as Star City’s vigilante and in his stead is John Diggle’s son, Connor Hawke.

In the brief time that he appeared on-screen, Connor Hawke seemed the consummate hero, the perfect blend of both his father and Oliver Queen. Since then, the character has yet to so much as receive mention. Should he ever return to the Arrowverse, it would assuredly be surprising.

14 GOLDEN GLIDER

The Flash Golden Glider

Lisa Snart/Golden Glider’s role in The Flash is minimal, but because she’s Leonard Snart’s sister, she makes a handful of appearances throughout the first two seasons. However, the character lacks substance, which is a shame, since her and Cisco build an intriguing bond. Furthermore, the brother and sister dynamic between Golden Glider and Captain Cold is fascinating.

As far as anyone knows, she’s still alive and probably hasn’t abandoned the life of crime. Were she to return to The Flash, it would be an interesting rollercoaster ride for both her and Team Flash, considering Captain Cold’s death in Legends of Tomorrow. Considering that no one seems to be begging for her return, Golden Glider is likely to remain one of the show’s long lost antagonists.

13 FIREFLY

Firefly on Arrow

Garfield Lynns' Arrowverse debut occurs early in Arrow’s first season, during “Burned.” The character’s tragic backstory makes him one of the series’ most compelling villain-of-the-week characters. However, Firefly’s status as a one-off foe ensures he does not take a comfortable place on anyone’s list of favorite Arrowverse villains.

Unless Barry tears apart the timeline, again, or Firefly appears on a different Earth, he is unlikely to return to the franchise. Admittedly, his absence from the series hasn’t been a total loss. Even in the comics, Firefly is a minor player in the grand scheme of things. Still, it would’ve been incredible to see this intriguing character’s story fleshed out a bit more.

12 LUCY LANE

Supergirl's Lucy Lane

Supergirl’s move from CBS to The CW after it’s pilot season altered the show in myriad ways. Because the shooting location changed from Los Angeles to Vancouver, a bulk of the secondary cast was lost and one such character is Lois Lane’s baby sister, Lucy Lane.

While at first her appearances on the show are limited, as she’s relegated to being James Olsen’s love interest, Lucy does eventually come into her own. Similar to the most famous of the Lane sisters, Lucy’s drive and determination carries much of her character arc forward. She eases into a position of power within the DEO and becomes a confidant to the Girl of Steel. Sadly, it doesn’t seem the character will be explored any further.

11 TRAJECTORY

Trajectory on The Flash

Every season of The Flash introduces a new speedster to the Arrowverse and the show’s sophomore effort will likely be most remembered for debuting Zoom. However, there was another speedster brought into the fray as well -- Trajectory. In the episode titled after her alter ego, Eliza Harmon experiments with the speed enhancement, Velocity 9. Consuming it is dangerous, but does give the user speed abilities for a short period of time.

Depicted as a villain, Trajectory wreaks havoc on Central City in an effort to gain access to more of the substance. Ultimately, The Flash defeats her, but she does leave a lasting impact on the series -- Jesse Quick’s suit design is evidently derived from Trajectory’s.

10 DOLLMAKER

Michael Eklund's Dollmaker on Arrow

Dollmaker is pretty standard comic book fare for a vigilante’s antagonist. He’s a criminal with an incredibly bizarre MO, who takes young women and turns them into doll-like figures and proves to be a rather difficult foe for Team Arrow to manage in season two Still, Dollmaker’s reign of terror only lasts for one episode.

Because he falls by Canary’s hand at the end of the episode, there’s never been a reason for Dollmaker to receive further mention. In the comics, however, he does have family members that follow in his stead. It seems unlikely that any of them will ever appear. Thus, remembering the enthralling narrative and high stakes the villain brought to the show will have to do for now.

9 INDIGO

Supergirl and Indigo

Indigo, otherwise known as Brainiac-8, proves a challenge for Supergirl in the back half of the show’s first season. Supergirl’s Kryptonian abilities are sometimes incapable of matching Indigo’s technology-based powers blow for blow. However, the battle is eventually won.

It’s difficult to imagine a Coluan as forgettable, considering Braniac’s history with Superman. For some reason, though, Indigo doesn’t seem to be regarded as one of Supergirl’s memorable villains. Perhaps this is because it feels as though she never existed. Following the show’s move to The CW, much of the lore established during season one is never officially reintroduced. Those events remain canon, but Supergirl itself has ignored the happenings.

8 PIED PIPER

Pied Piper on The Flash

Pied Piper appears for a short time during The Flash’s first season, then returns briefly in season two. As Caitlin’s and Cisco’s old colleague, as well as Harrison Well’s protégé, this villain proves quite the match for Team Flash. At first glance, his ability to manipulate sound waves may not seem like much of a force to be reckoned with. Yet, pair Pied Piper’s sonic technology with his craftiness, and he’s deadlier than he appears.

It’s unfortunate, then, that the character hasn’t been heard from since his brief season two return. Considering plenty of time has passed, it’d be interesting to see the character’s growth. Since villain-of-the-week types seldom recur, Pied Piper’s post-Team Flash adventures may remain a mystery.

7 CLOCK KING

Clock King in Arrow Season 2

Clock King was originally introduced as a minor villain during Arrow’s second season. The time-obsessed foe returned in The Flash’s first run, connecting the two shows in an interesting fashion. While his behavior makes him especially compelling to watch, Clock King’s heartbreaking story also warrants attention.

This villain could be considered the hero of his own story. Perhaps it’s even fair, to some extent, to regard him as anti-heroic. Clock King himself is terminally ill. However, his primary goal is to obtain enough money for his ailing sister’s treatment. Yes, his actions are criminal, but that does not make Clock King’s motives any less admirable.

6 SILVER BANSHEE

Silver Banshee Supergirl Season 1

Siobhan Smythe is one of Supergirl’s more interesting recurring characters, despite only starring in a few episodes for the show’s pilot season. Her evolution as Cat Grant’s overly ambitious assistant into the villainous Silver Banshee remains a compelling facet of the series. The character’s arc is organic in its development. She arrives as the new assistant trying to impress Cat Grant, but a desire to advance at a quick pace results in her sabotaging her own career.

Siobhan acts as the perfect foil to Supergirl. However, her malevolent Silver Banshee persona doesn’t incite as much excitement. Thus far, this villain hasn’t appeared since the show’s move to The CW, which is a shame. Silver Banshee would make for an intriguing recurring character à la Captain Cold or Damien Darhk.

5 SIMON STAGG

Simon Stagg isn’t that big of a name in the DC Universe, however he is integral to other big name characters. For instance, Rex Mason’s work with Simon Stagg eventually leads to Rex’s transforming into Metamorpho. This, of course, does not occur on The Flash, but Stagg’s technology company in Central City, Stagg Industries, does engender the creation of the villain, Multiplex.

By the end of the episode in which he appears, season one’s “Fastest Man Alive,” Stagg falls at the hand of Harrison Wells. Stagg’s demise is most notably disappointing, since it means Metamorpho won’t likely debut in the Arrowverse. Stagg’s absence also adds to the franchise’s trend of prematurely killing off DC’s important scientists -- others include Anthony Ivo and Dr. T.O. Morrow.

4 ANTHONY IVO

Anthony Ivo on Arrow

Anthony Ivo may not be particularly well known, but the character’s technology-centric work is instantly recognizable. His most notable scientific accomplishment is none other than Amazo, an android with the ability to adopt the powers of other superpowered beings. Surprisingly, Amazo has yet to appear on any of the Arrowverse series. Interestingly, Arrow’s second season, the only time in which Ivo is present, does feature an incredible easter egg. The name of the ship Ivo docks near Lian Yu is named “Amazo.”

Similar to his comic counterpart, this version of Ivo is a scientist. In wanting to save his wife’s life, he experiments with Mirakuru -- the substance responsible for Deathstroke’s abilities. It’s too bad that Arrow limits Ivo’s use to one storyline.

3 PARASITE

Parasite on Supergirl

Parasite debuts early in Supergirl’s sophomore season, during “Changing.” Rudy Jones is a scientist working in the Arctic whose team comes in contact with an alien parasite. By the time Supergirl and the DEO arrive at the site, it’s too late. Everyone on Rudy’s crew, excepting Rudy himself, is gone. Upon returning to National City, the scientist begins exhibiting symptoms caused by the parasite as it’s taken over his body.

It’s a fun episode and Parasite certainly makes for a formidable villain. As one of Superman’s more captivating foes, Parasite brings an interesting dynamic to Supergirl’s lore. Sadly, he doesn’t stick around for long. But he does return for the Valentine’s Day episode, where Mr. Mxyzptlk summons him in an effort to woo Kara.

2 CAPTAIN BOOMERANG

Captain Boomerang on Arrow

Despite being known as one of The Flash’s rogues, the Arrowverse’s Digger Harkness/Captain Boomerang has only ever appeared on Arrow. Crossover episodes allow him to fight opposite the Scarlet Speedster, though. Regardless of what show he features on, everyone can probably agree on Captain Boomerang’s being underused. Might his limited appearances have something to do with the live-action Suicide Squad film? It’s possible.

Unfortunately, the villain's passing in Arrow’s fifth season finale means he won’t return. However, the Arrowverse does occasionally reintroduce characters by way of the multiverse or time travel. Perhaps we haven’t seen the last of this Flash foe. But if it truly is over for the notorious thief, it’s a shame he never received a chance to shine.

1 RAGMAN

Arrow's Ragman

Ragman joins Team Arrow at the start of Arrow's fifth season. Admittedly, he's an odd addition, but it works for the most part. During that season’s midseason finale, Ragman leaves the team. His reasoning? The suit he dons, which has some sort of mystical power, is damaged after he uses it to absorb the blast from a massive explosion. The hero’s been gone since then and, apparently, no one on Team Arrow has heard from him.

If fans have forgotten about Ragman, it’s because his teammates have done the same. No one mentions him, or even recalls his heroics in the short time he spent on the team. In this regard, Ragman’s absence from the show is pretty sad.