Batman: The Animated Series called "Joker's Favor." Harley's creator Paul Dini was inspired to create her based on a scene from soap opera Days Of Our Lives, where actress Arleen Sorkin played a jester. Sorkin would go on to voice the role, which was originally intended as a one-off henchwoman. Harley proved popular with viewers so she became a recurring villain and the show later dug into her backstory, revealing she was once a psychiatrist who fell in love with the Joker while treating him.
Harley Quinn later received her own comic series and developed a cult fandom. That said, it took a while for her to make her big-screen debut. Both Madonna and Courtney Love were rumored for Harley in Joel Schumacher's canceled sequel Birds Of Prey.
In 2009 the video game Batman: Arkham Asylum arrived and is rightfully considered one of the best gaming adaptations of the character. It featured a great story and fluid combat, and it spawned sequel and prequel games. In also received an animated spinoff with 2014's Batman: Assault On Arkham. The plot finds Amanda Waller assembles a misfit team of criminals - including Harley, Deadshot, Captain Boomerang and others - to break into Arkham and steal critical information. While he's not a main character, Batman himself (Kevin Conroy) plays a key ing role.
While the protagonist of Adventure Time), this Harley is fresh from a break-up with Joker and during a mood-setting intro, bites the ear off a nurse who tries to stop her watching cartoons. Assault On Arkham's Harley is quite unhinged but she owns it and is the only member of the team excited by the mission. She loves being airdropped from a plane while the others scream in horror and even enjoys the electroshock treatment needed to disable out Waller's bomb in her neck.
It also makes sense for Harley to lead the heist in Batman: Assault On Arkham, since she used to work at the asylum and knows its layout and secrets. It also explores the darkness of her relationship with Joker, which is something the Suicide Squad movie itself shied away from. She expresses hate for Joker and even tries to kill him during the initial part of the heist, but returns to his side when he escapes, even when he berates her. This complex dynamic would be explored further in the game series, especially following the ending of Batman: Arkham City. Batman: Assault On Arkham's Harley Quinn tends not to get much attention, but its underrated take on a beloved character.
