Harley Quinn

QUICK BIO
Once a brillant psychiatrist, Harley Quinn was recruited by the Joker whileinterning at Arkham Asylum. Renaming herself to be suited for his insanecircus, she helped the Joker escape. Though she hides her true nature behinda mask of playfulness and fun, she is almost as deadly and unpredictable asher infamous boss.

SOURCE:Batman: The Animated Series