Robert Underdunk Terwilliger, better known by his stage name 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", although his first major appearance was in "Krusty Gets Busted". Sideshow Bob has been described as "Frasier pickled in arsenic" Frasier being Grammer's character on the series Frasier. In 2006, Grammer won an Emmy for Outstanding Voice-Over Performance for his portrayal of Bob in the episode "The Italian Bob." Sideshow Bob was originally the sidekick on Krusty the Clown's television show, but Krusty's continuous abuse led to Bob framing him for armed robbery. Krusty was arrested and Bart Simpson discovered that Bob was behind the crime, leading to Bob's arrest. Since then he has been a villainous homicidal maniac, as well as Bart's mortal enemy, and as a result he has tried to kill Bart on several occasions. Bob has been featured in ten episodes, with the most recent one airing during the nineteenth season.