Harley Quinn was created by Paul Dini and Bruce Timm for the 1992 Batman: The Animated Series episode entitled "Joker's Favor" while Dini was writing the episode. Initially written as an animated equivalent of a walk-on role, Harley Quinn was intended to appear in just one episode. With this, her origin was not supposed to be more than it was, making her popularity unexpected and a surprise success. As Dini was putting together the story for the episode, he wanted to introduce a foil for the supervillain the Joker that would emphasize the Joker's comic book personality traits: funny, scary, and egotistical. He then thought of giving Joker a henchwoman, inspired by the molls of the 1960s live-action Batman series, and then decided she would be a "funny counterpart to the Joker to maybe work up a little Punch and Judy attitude between them"; Dini stated, " she could crack a joke and the henchmen would laugh, and the Joker would kind of glare at her". The character idea dated back in 1991, when Dini witnessed his college friend Arleen Sorkin play a jester in an episode of Days of Our Lives. Dini then based Harley Quinn on Sorkin, incorporating aspects such as her mannerisms and "snappy, wisecracking, bubbly blonde" personality. Dini even decided to have Sorkin voice her. In recording Harley Quinn's voice, Sorkin spoke in her normal New York accent while putting in a "little Yiddish sound", since Dini made the character Jewish, another aspect of the character borrowed from Sorkin; Dini described her voice for the character as having "a snappy blonde but also kind of a bad girl": "a little bit of Adelaide from Guys and Dolls, a little bit of Judy Holliday", and "a lot of Arleen", stating that it sounded "very close" to Sorkin's voice.