Batman: The Killing Joke is a graphic novel written by Alan Moore and illustrated by Brian Bolland. It is a dark and psychological story that delves into the complex relationship between Batman and his arch-nemesis, the Joker. The Killing Joke is known for its gritty artwork and its exploration of the Joker's origins and motivations. It is considered one of the definitive Batman stories and has had a lasting impact on the character and the comic book industry as a whole.