Born in Brooklyn, Harleen Quinzel would graduate college as a criminal psychiatrist. She would then be transferred to Arkham Asylum as a psychiatrist where she met the Joker and have sessions where he would open up to her. The two would then escape where she would be shoved into the an Ace chemicals tank. The two would then be the King and Queen of Crime. After some time, she would eventually leave him to be her own.

Harley has Blue Eyes, Blonde Hair with Pink and Blue Pigtails and Fair Skin.