Harvey Dent

Half man and half madman, Two-Face was the alias of former Gotham City District Attorney Harvey Dent. After receiving brain damage by a mobster's acid, Dent became a bloodthirsty, eccentric, homicidal maniac with a penchant for using a coin to determine all of his actions. The trauma combined with Batman's failure to protect him shattered his psyche. Thus, the vengeful, psychotic crime lord known as "Two-Face" was born.