While Batman is undoubtedly the most popular characters in Gotham City, there are a number of other heroes and villains from DC's dark city like Harley Quinn that have managed to reach their own levels of mainstream popularity and appeared outside of the comics in a number of animated or live-action film and TV appearances.

RELATED: Harley Quinn: 10 Major Ways She Changed Over The Years

Of course, Harley Quinn is a little unique in that area given that she first appeared on TV before her growing popularity resulted in her eventual appearance in the DC comics continuity, and as her star has continued to rise she has begun to appear outside of the comics both on her own and as a member of the Suicide Squad.

Updated on May 31st, 2021 by the author: Harley Quinn's evolution into a heroic member of the Bat-Family in the comics has been somewhat represented by her appearances across other mediums like movies and television. Her ongoing popularity makes Harley Quinn one of the most profitable characters in DC's roster which has led to her survival on the big screen with continuing appearances as well as multiple seasons of her own animated series, which managed to survive the cancelation of the DC Universe streaming app. This update adds a few more of Harley Quinn's extensive collection of live-action and animated appearances to celebrate the Mistress of Mayhem.

15 A Character Named Ecco Was A Prototype Version Of Harley Quinn That Appeared On Gotham

Ecco walking through a graveyard on Gotham

Fox's prequel series Gotham took place in DC's iconic city years before the arrival of Batman, and it explored the development of Jim Gordon's career with the GCPD and the evolution of the Dark Knight's future villains.

Unfortunately, the series was prohibited from officially using certain villains like the Joker or Harley Quinn, and instead introduced unique "proto" versions of the characters. Francesca Root-Dodson played a character known as Ecco who worked for Jerome/Joker and featured similar qualities and designs as Harley Quinn, though she was killed off in the final season.

14 Harley Quinn Has A Number Of Live-Action & Animated Cameos

Harley Quinn cameos in live-action and animation

Harley Quinn has also appeared in a number of cameos over the years in the background of numerous Teen Titans Go! episodes and 2018's Teen Titans Go! To The Movies, as well as 2018's Ready Player One.

Tara Strong voiced "Deranged Squad Female" for a quick Harley cameo (played by Cassidy Alexa) on The CW's Arrow, though her full appearance was canceled. Harley would briefly appear in 2017's The Lego Batman Movie voiced by Jenny Slate, and then again in 2019's The Lego Movie 2: The Second Part, voiced by Margot Rubin.

Two versions of Harley Quinn on DC Super Hero Girls

The success of the original short led to the first season of DC Super Hero Girls in 2019, which reimagined popular female heroes and villains as teenage high school characters that form a superpowered crime-fighting team in Metropolis.

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Harley Quinn (voiced again by Tara Strong) first appeared as Barbara Gordon/Batgirl's best friend Harleen before she later debuted her villainous alter-ego. Harley's costume has been modified along with the rest of the characters to reflect modern fashion trends and her friendship with Poison Ivy is featured.

12 Mia Sara Starred As Dr. Harleen Quinzel On TV's Birds of Prey In 2002

Birds of Prey Mia Sara Harley Quinn

It might be surprising to some fans of Harley Quinn to know that she first appeared in a live-action Birds of Prey series way back in 2002, years before the character would star alongside the superhero team on the big screen.

Mia Sara portrayed Dr. Harleen Quinzel in the short-lived series as a psychologist and behind-the-scenes crime boss plotting to take over the city of New Gotham. Mia Sara's unique take on the character never really wore a costume on the series, though her final outfit did feature a familiar motif.

11 Harley Quinn Made A Brief Appearance In A Bonus Scene From 2017's Batman Vs. Two-Face

Dr Harleen Quinzel and Harley Quinn in Batman vs Two-Face

Following the success of Batman: Return of the Caped Crusaders that was set in the Batman '66 continuity and featured the reunion of Adam West and Burt Ward from the hit TV series, a sequel was created called Batman vs. Two-Face that introduced the classic Gotham City villain into that universe for the first time.

While the focus was on Two-Face, Dr. Harleen Sorkin appeared in the movie as Professor Hugo Strange's assistant, though in a bonus scene on the Blu-ray release, she suited up in a new take on the Harley Quinn outfit to bust The Joker out of prison to likely tease another movie, though the death of Adam West likely brought those plans to an end.

10 Batman: The Brave and The Bold Gave Harley Quinn A 1950s-Style Overhaul

Harley Quinn, Joker and Poison Ivy in Batman The Brave and The Bold

Cartoon Network's Batman: The Brave And The Bold took its name from a team-up comic series and followed a similar premise as Batman worked with a different character or team in each episode that touched on all eras of the DC universe.

RELATED: The Batman: 5 Best Animated Villain Redesigns (& The 5 Worst)

Harley Quinn (voiced by Meghan Strange) appeared in a 50s-themed "flapper girl" motif in her only series appearance. However, the character would return in the direct to video Scooby-Doo! & Batman: The Brave And The Bold, voiced by Tara Strong.

9 A Modernized Take On Harley Quinn Appeared On The Batman Alongside The Joker

Harley Quinn and The Joker on The Batman animated series

2004 saw the release of The Batman, which was the first new animated take on the Dark Knight since the hugely successful 90s series that took a wildly different approach to character design that also reimagined some of the character's backstories.

Harley (voiced by Hynden Walch) was now the host of a psychology talk show who quickly became a target for the Joker after she publicly lost her series. She wore a modified version of her original jester costume, though Harley never quite moved past the role of Joker's partner over her various appearances in the series.

8 Harley Quinn Was Mutated Into A Hyena In 2019's Batman vs. Teenage Mutant Ninja Turtles

Harley Quinn transformed into a hyean in Batman vs Teenage Mutant Ninja Turtles

The Dark Knight crossed over with the heroes in the half-shell in 2019's Batman vs. Teenage Mutant Ninja Turtles, which was based on the successful comic crossover though there were many differences between the two projects.

Tara Strong returned to the role which saw Harley Quinn working alongside The Joker who had managed to create a new form of mutagenic Joker toxin that transformed Gotham City's villains into animal/human hybrids, with Harley Quinn was fittingly mutated into a spotted hyena.

7 Harley Quinn Frequently Worked With Poison Ivy In Justice League Action

Harley Quinn robbing a jewelry store in Justice League Action

Tara Strong reprised her role of Harley Quinn in Justice League Action, which united DC's Trinity (Superman, Batman, and Wonder Woman) with less developed members of the League in quick kid-friendly episodes that homaged previous animated versions.

RELATED: 10 Reasons Why Batman: Knightfall Should Join DC's Animated Movie Universe

This was true with Harley Quinn as well, who wore her classic jester costume and featured a wide variety of cartoon-like weaponry that captured the character well. She was also a frequent ally of Poison Ivy instead of the Joker on the series, showcasing her far superior relationship.

Harley Quinn in Birds of Prey

Margot Robbie returned as Harley in 2020's Birds of Prey (And The Fantabulous Emancipation of One Harley Quinn), which was later retitled Harley Quinn: Birds of Prey after the initial release of the film.

While Birds of Prey featured the first theatrical adaptation of the titular female superhero comic team, it also explored Harley's life after the Joker. Harley didn't really wear any costumes in the film, though a few of her looks were inspired by her New 52 roller derby-influenced costume. She also adopted her first hyena that she named Bruce, after "that hunky Wayne guy."

Harley Quinn appearances in the DCAMU

The DC Animated Movie Universe features over thirty films that have adapted comic storylines alongside new original stories in feature-length direct-to-video releases that feature a few different versions of Harley Quinn across various shared continuities.

She appeared as a member and eventual leader of Task Force X in films like 2018's Suicide Squad: Hell To Pay and 2020's Justice League Dark: Apokolips War, voiced by Tara Strong and Hynden Walch, respectively. 2018's Batman Ninja (Rie Kugimiya/Tara Strong) introduced fun multiversal versions of the character.

4 Batman: Assault On Arkham Focused On The Video Game Version Of Harley Quinn And The Suicide Squad

Harley Quinn in Batman Assault on Arkham

The Dark Knight starred in 2009's hit Batman: Arkham Asylum which launched a successful franchise that led to the animated prequel movie Batman: Assault on Arkham that assembled that universes version of the Suicide Squad.

RELATED: 10 Things You Didn't Know About The Joker & Harley Quinn's Relationship

Harley Quinn appeared alongside frequent members like Deadshot and Captain Boomerang that borrowed heavily from the New 52 take on the team that increased Harley's sexuality and introduced a romantic relationship between her and teammate Deadshot.

3 Margot Robbie Brought Harley Quinn To The Big Screen In 2016's Suicide Squad

Harley Quinn holding her mallet in Suicide Squad

2016's Suicide Squad introduced Task Force X to the DC Extended Universe and adapted a number of comic villains to live-action for the first time, which included Harley Quinn, played by Margot Robbie.

Suicide Squad explored Harley's origins with Jared Leto's Joker and even teased her original jester outfit in an homage to the cover of her comic debut. Her actual movie costume was original though inspired by her New 52 comic makeover. Robbie is set to reprise her role as Harley Quinn in James Gunn's upcoming The Suicide Squad.

2 Harley Quinn's Debut On Batman: The Animated Series Led To Many Appearances In The "Timmverse"

Harley Quinn leaning against the Batmobile

While Harley Quinn debuted in 1992's Batman: The Animated Series (voiced by Arleen Sorkin), the character has grown so much over the years that she might not be instantly recognizable to some fans of the comics, though the core traits of the character never wavered far from their beginnings in the animated Timmverse.

Harley Quinn would go on to appear in Superman: The Animated SeriesThe New Batman AdventuresBatman Beyond (and the related Return of the Joker film), and Static Shock. The Timmverse version would later return in 2017's Batman and Harley Quinn film, voiced by Melissa Rauch.

1 Harley Quinn Formed Her Own Villainous Gang In Her Titular Animated Series

Harley Quinn holding a bat in her animated series

The most faithful adaptation of the current comic version of Harley Quinn is her own self-titled animated series, which began airing in 2019 on DC Universe before moving to HBO Max for the upcoming third season.

The uncensored adult animated series stars Kaley Cuoco as Harley Quinn alongside her own gang of Gotham baddies as she makes a name for herself after a contentious split with the Joker. The series also stars Poison Ivy and has featured their romantic relationship in ways even the comics have yet to fully explore.

NEXT: DC: 10 Best Versions Of Harley Quinn