Harley Quinn: E-1

Harley Quinn of Earth-1 is the daughter of Jack Napier AKA The Joker. She was born after his death at the hands of Batman in 1989. Her mother had been driven insane prior to her birth. It seemed Jack's altered DNA by his exposure to Axis Chemicals had been passed on to his daughter who had been diagnosed as clinically insane from the age of 12. She escaped from Arkham Asylum when she was 25 and took the name Harley Quinn to honor her father, and swore revenge on Batman.