Sideshow Bob oikealta nimeltään Dr. Robert "Bob" Underdunk Terwilliger, Jr. Bob oli sivunäyttelijänä hassun televisio-ohjelmassa, kunnes hän lavasti hassun Apun kaupan ryöstöstä ja joutui näin vankilaan. Sideshow Bobin tilalle ohjelmaan valittiin Sideshow Mel.Sideshow Bob yrittää vielläkin tappaa Barttia. Sideshow Bob puhui Italiaa jaksossa (Italian Bob). Luokka:Simpsoneiden hahmot
Sideshow Bob is acharacter in the Simpsons that triesto kill Bart. He first appeared inthe Telltale Head.
Robert Underdunk Terwilliger Jr, better known as Sideshow Bob, is the secondary antagonist of the animated TV series The Simpsons. He is Bart's archenemy. He was originally Krusty the Clown's sidekick until he framed Krusty for robbing the Kwik-E-Mart, however he was foiled by Bart Simpson who exposed Bob's scheme. And ever since then Bob has vowed to kill Bart, though on some occasions he has also gone after Krusty. He is voiced by Kelsey Grammar who also played Stinky Pete in Toy Story 2, Harold Attinger in Transformers: Age of Extinction, and Hunter in Storks.