The Joker is a fictional character and one of the most iconic villains in comic book history, primarily associated with Batman. He is often depicted as a psychopathic criminal mastermind with a clown-like appearance, characterized by his white skin, green hair, and a wide, red smile. The Joker's unpredictable nature and dark sense of humor make him a formidable adversary for Batman. His origins vary across different stories, but he is typically portrayed as a former criminal who falls into a vat of chemicals, leading to his disfigurement and insanity. The Joker's antics often involve elaborate schemes and a penchant for chaos, making him a symbol of anarchy and madness in the DC Comics universe.