Created by Paul Dini and Bruce Timm to serve as a new supervillain and a romantic interest for the Joker in Batman: The Animated Series in September 1992, Harley Quinn was later adapted into DC Comics' Batman comic book canon, beginning with The Batman Adventures #12 (September 1993).
Harley Quinn is a frequent accomplice and lover of the Joker, who was her patient when she worked as an intern psychiatrist at Gotham City's Arkham Asylum. Her alias is a play on the name "Harlequin", a character that originated in commedia dell'arte. She has also teamed up with fellow villains Poison Ivy and Catwoman, the trio being known as the Gotham City Sirens; Ivy is a close friend and occasional girlfriend of Harley. Since The New 52 comics, she has been depicted as an antihero and a recurring core member of the Suicide Squad who has left her abusive relationship with the Joker behind; however, in other media, the character is still depicted as a supervillain.