Dr. Robert Underdunk Terwilliger, PhD, better known as Sideshow Bob, is a recurring character in the animated television series The Simpsons. He is voiced by Kelsey Grammer and first appeared briefly in the episode "The Telltale Head". Bob is a self-proclaimed genius who is a graduate of Yale University, a member of the Republican Party, and a champion of high culture. He began his career as a sidekick on Krusty the Clown's television show, but after enduring constant abuse, Bob attempted to frame his employer for armed robbery in "Krusty Gets Busted". The plan was foiled by Bart Simpson, and Sideshow Bob was sent to prison. Bob made his second major appearance in season three's "Black Widower"; the writers echoed the premise of the Coyote chasing the Road Runner by having Bob unexpectedly insert himself into Bart's life and attempt to kill him. In each appearance thereafter, Bob has assumed the role on The Simpsons of an evil genius. Episodes in which he is a central character typically involve Sideshow Bob being released from prison and executing an elaborate revenge plan, usually foiled by Bart and Lisa.