Harley Quinn is an anti-heroine from DC Comics, usually a partner of The Joker, this version hailing from the Prime Earth no longer has any conection with him.
Dr. Harleen Quinzel was a psycologist from Arkham Asylum who was called to attent the Joker, who unknown to her was manipulating her to became her partner.
She was corrupted by the Joker throw her into Chemical vats (exactly what happened to him) and turned her into his henchwoman Harley Quinn. Over the years, they commited crimes until Joker decided that she was no longe useful to him, which she defend against him is no longer a villain once more.
Harley Quinn is the definition of crazy and madness, turning to a life of crime. She was very happy indulging in every criminal activity, however over the years (and some help of Batman), she has become an antiheroine thus far, even allying herself with Power Girl at one point.
In current days, she has worked with the Suicide Squad and even defeated the Joker proving she is no longer controlled by him.
- Harleen Quinzel (Prime Earth) appears as Harley Quinn (Prime Earth) a playable character in the Infinite Crisis video game.