The Simpsons season 12 episode 13
Episode title: Day of the Jackanapes
Krusty announces his retirement due to interference from network executives and the growing popularity of the big-money game show "Me Wantee", but when Krusty reveals to Sideshow Bob that all of the episodes featuring him have been erased, Sideshow Bob uses Krusty's biggest fan (Bart) to murder him during Krusty's farewell show.