Harley is the former girlfriend and sidekick of The Joker, and is currently dating her best friend Poison Ivy. Since dumping Joker, she has led and founded a ragtag crew of villainous misfits, and is a former member of the Legion of Doom. At the end of season 3, Harley realizes she does not feel like a villain anymore, and decides to join the Bat Family while Bruce Wayne is serving his prison sentence.