Harley Quinn

The Joker's former psychiatrist, turned DC's breakout antiheroine.

Harley Quinn is Dr. Harleen Frances Quinzel, a former Arkham Asylum psychiatrist who was manipulated by her patient, the Joker, and became his accomplice and lover. Paul Dini and Bruce Timm created her as a henchwoman for Batman: The Animated Series, where she debuted in the episode "Joker's Favor" on September 11, 1992. Meant for a single episode, she became a regular and entered DC Comics canon with Batman: Harley Quinn #1 (October 1999). Her name plays on the Harlequin of commedia dell'arte.

She is an expert gymnast and fighter, immune to toxins, swings an oversized mallet and keeps two pet hyenas, Bud and Lou, and later stories made her a close friend and love interest of Poison Ivy. DC publisher Jim Lee has called her the fourth pillar of the line after Superman, Batman and Wonder Woman. Margot Robbie played her in three DC Extended Universe films and Lady Gaga in Joker: Folie a Deux.

Quick Facts

Real name: Dr. Harleen Frances Quinzel
Creators: Paul Dini and Bruce Timm
First appearance: Batman: The Animated Series, "Joker's Favor" (September 11, 1992)
First comic appearance: Batman: Harley Quinn #1 (October 1999)
Signature weapon: Oversized mallet
Pets: Hyenas Bud and Lou

Facts from the source article.