The Joker is a character.
The Joker is a fictional supervillain created by Bill Finger , Bob Kane , and Jerry Robinson who first appeared in the debut issue of the comic book Batman ( April 25 , 1940 ) published by DC Comics . Introduced as a psychopath with a warped , sadistic sense of humor , the character became a goofy prankster in the late 1950s in response to regulation by the Comics Code Authority , before returning to his darker roots during the early 1970s . The character 's popularity has seen him appear on a variety of merchandise , such as clothing and collectable items , inspire real-world structures ( such as theme park attractions ) , and be referenced in a number of media .