Harley Quinn's first major appearance outside the animated series was in the Elseworlds mini-series "Thrillkiller." As with the other characters, her background is very different to the one established in the animated series. In this comic, she is a schoolgirl named Hayley Fitzpatrick who dresses up to help a female version of the Joker. After Batgirl kills the Joker, Harley is shown killing her own family, intent on revenge in the final frames of the story.
