Harvey Dent was Gotham City's amiable and courteous district attorney and one of Batman's strongest allies (until Sal "Boss" Maroni threw acid in his face, hideously scarring him). It also fractured his mental state, causing him to become Two-Face, a criminal mastermind obsessed with duality and the number two and is one of Batman's greatest enemies. His former good luck charm, a "two-headed" silver dollar with one side defaced, has been seen as a reflection of Dent's half-scarred visage.