Harley Quinn (Harleen Frances Quinzel) is a character appearing in American comic books published by DC Comics. Harley Quinn was created by Paul Dini and Bruce Timm as a humorous henchwoman for the supervillain Joker in Batman: The Animated Series, and debuted in the 22nd episode of the series on September 11, 1992. While originally intended to appear in one episode, she became a recurring character within the DC Animated Universe as the Joker's sidekick and love interest, and was adapted into DC Comics' Batman comic book canon, beginning with the one-shot Batman: Harley Quinn #1 (October 1999). The character's alias is a play on the stock character Harlequin from the sixteenth-century theater commedia dell'arte. Following her introduction to the DC universe in 1999, Harley Quinn was depicted as a frequent accomplice and lover of the Joker as well as a close friend of fellow supervillain Poison Ivy, the former being one of her patients when she worked as an intern psychiatrist at Gotham City's Arkham Asylum. The character has been part of a short-lived alliance with Poison Ivy and Catwoman, the trio being known as the Gotham City Sirens. Since 2013, Harley Quinn has often been depicted as an antihero and a recurring core member of the Suicide Squad who has left her abusive relationship with the Joker behind, with Poison Ivy becoming her primary romantic interest. Harley Quinn's abilities include expert gymnastic skills, proficiency in weapons and hand-to-hand combat, complete unpredictability, immunity to toxins, and enhanced strength, agility, and durability. The character has a pair of pet hyenas, Bud and Lou, which sometimes serve as her attack dogs. As a trained psychiatrist with a genius level intellect, she is adept at deception and psychological manipulation. Since her conception, Harley Quinn has become one of DC Comics' most popular and profitable characters, and has been featured in many of DC's comic books.