The Joker with Green Hair Key Chain with Lego Logo Tile, Modified 3 x 2 Curved with Hole
In the , the Joker is portrayed as a criminal mastermind and the antithesis of Batman in personality and appearance. He was introduced as a with a warped, sense of humor but became a comical prankster in the late 1950s in response to regulation by the , before returning to his darker roots during the early 1970s. The Joker has been part of defining Batman stories, including the murder of —the second and Batman's ward—in "" (1988) and the paralysis of —the first —in (1988). Unlike many comic book characters, the Joker does not have a definitive origin story, but various possible ones have been developed. The most common story involves him falling into a tank of chemical waste that bleaches his skin white, turns his hair green and lips red, and leaves him with a rictus grin; the resulting disfigurement drives him insane.
