The joke’s on Batman this year. Fans of the Caped Crusader usually celebrate Batman Day on September 23, but this year his thunder has been stolen by a young woman wielding a giant mallet and wearing a broad grin. On September 11, Harley Quinn turns 25 years old – and the former psychiatrist who turned to the dark side in 1992 as a sidekick to The Joker celebrates her silver anniversary as a fully rounded DC Comics multi-platform villainess.
But who is Harley Quinn – and why is a relative newcomer being granted a privilege usually afforded to the most celebrated

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