“Beyond the classic rock and askew appeal of the two trailers released to date, one thing is obvious about Warner Bros’ Suicide Squad: it will raise the profile of DC Entertainment’s Harley Quinn even higher, with Margot Robbie’s off-kilter take on the character that started life as a one-time sidekick of the Joker sure to push the character even further into the spotlight.
Unusually for a character so entrenched in the DC Universe, Harley’s first appearance wasn’t in a comic book – instead, she debuted in the 1993 22nd episode of the 1990s Batman: The Animated Series, “Joker’s Favor.” Quinn’s creation was an afterthought on the part of writer Paul Dini; a gag involving the Joker leaping out of a cake was deemed not fitting for the criminal, and Harley was invented to fill the role instead.
Thanks in large part to the vocal performance of Arleen Sorkin – a friend of Dini’s and, according to interviews, a model for how he envisioned the character – Harley quickly became a favorite both of viewers and those working on the series, returning a number of times both in and out of the company of the Joker. In fact, the character became so popular that she was the subject of Mad Love, a 1994 spinoff graphic novel set in the animated series’ continuity by Dini and the show’s art director Bruce Timm that revealed her origin story.
Mad Love didn’t just introduce the backstory of Harley – a former psychiatrist called Harleen Quinzel, she fell in love with the Joker while interning at Arkham Asylum and freed him in an attempt to win his heart – it also showed how easily the character could support the weight of a story by herself when given the chance. It’s unlikely to be a coincidence that she starred in her first animated episode without the Joker (Season 2’s “Harley’s Holiday”) soon after the release of the book…”