Joker

The Joker is a fictional character that appears in the comic book published by DC Comics. The character first appeared in Batman #1 (Spring 1940), and was created by Bill Finger, Bob Kane and Jerry Robinson. The Joker is a master criminal, initially portrayed as a violent sociopath who murder people and commits crimes for his own amusement. The character, later in the 1940s, began to be written as a goofy trickster-thief. That characterization continued through the late 1950s and 1960s before the character was again depicted as a vicious killer. The Joker is the archenemy of Batman, and has been responsible for numerous tragedies in Batman's life, including the paralysis of Barbara Gordon (Batgirl/Oracle) and the murders of Jason Todd (the second Robin) and Commissioner Gordon's second wife Sarah Essen. The Joker's real identity is unknown, and there have been different takes on his origin, though each depicts him as haven fallen into a vat of chemicals, which bleached his skin white,... full article at wikipedia