Harley Quinn was originally Harlene Quinzelle, a criminal psychologist. She meets the Joker, starts working with him and as she quotes "my whole life I had always listened to other people. Mr J. he listened to me". That began her saga as Harley Quinn, Jokers sidekick and lover, one of Batman's greatest female advosorys.
She shows her true colors in Harleyquinade where she teams up with batman, and is sweet, loveable, and funny. She gets mad at Joker at the end and its great how her "take no shit" attitude applies even to the Clown Prince of Crime. She teams up with Poison Ivy, and I dont think ill ever forget how much she hated the shots she had to take, so she wouldnt die in Ivy's toxic plant home. She charms her way out of problems, and drags guys around on leashes. If you ever get to see an episode she's in, consider yourself lucky.