Originally a psychiatrist at Arkham Asylum, Dr. Harleen Quinzel fell in love with the Joker. She started aiding him in escapes and eventually adapted the clown guise of Harley Quinn. However, her "Puddin'" refused to return her love and has tried to kill her on more than one occasion. After one such close call, she received help from her friend Poison Ivy, resulting in Harley's amazing acrobatic abilities. Like her would-be boyfriend Harley employs all manner of trick gadgets in her crimes.