Sideshow Bob

Sideshow Bob
The Simpsons character
First appearance	"The Telltale Head" (1990)
Designed by	Brad Bird
Voiced by	Kelsey Grammer
In-universe information
Full name	Robert Underdunk Terwilliger Jr.
Occupation	Former television personality Former mayor Criminal
Family	Dr. Robert Terwilliger Sr. (father) Dame Judith Underdunk (mother) Cecil Terwilliger (brother)
Spouses	Selma Bouvier (ex-wife) Francesca (ex-wife) Tasha (wife)
Children	Gino

Dr. Robert Underdunk "Bob" Terwilliger Jr., PhD, better known as Sideshow Bob, is a recurring antagonist in the animated television series The Simpsons. He is voiced by Kelsey Grammer and first appeared in the episode "The Telltale Head". A self-proclaimed genius and graduate of Yale University, Bob champions high culture and speaks with a transatlantic accent similar to the one Grammer uses as Dr. Frasier Crane in the sitcoms Cheers and Frasier. He began his career as a sidekick on Krusty the Clown's television show, but after enduring constant abuse, Bob framed his employer for armed robbery in "Krusty Gets Busted", only to be foiled by Bart Simpson and sent to prison. While imprisoned, Bob began seeking revenge against Bart, and the two became archenemies.

Bob's second major appearance came in season three's "Black Widower"; the writers echoed the premise of Wile E. Coyote chasing the Road Runner by bringing Bob back into Bart's life with another murderous scheme. Thereafter, Bob serves as the series' recurring evil genius, repeatedly emerging from prison with elaborate revenge schemes that Bart and Lisa usually foil. Bart remains his principal target, although his schemes also threaten Krusty and extend to the entire Simpson family in season 17. The Halloween story "Wanted: Dead, Then Alive", the first segment of "Treehouse of Horror XXVI" (season 27), imagines Bob finally killing Bart. Before the murder, he remarks that he has spent 24 years trying to kill a ten-year-old child; with Bart dead, he soon becomes bored and brings him back to life so that he can kill him repeatedly.

Sideshow Bob shares traits with Grammer's Crane and has been described as "Frasier pickled in arsenic." The resemblance extends to the casting: David Hyde Pierce and John Mahoney played Bob's brother Cecil and his father, respectively, echoing their roles in Frasier. Grammer, who based Bob's voice on that of actor Ellis Rabb, has been praised for his portrayal of Bob. In 2006, Grammer won a Primetime Emmy Award for voicing Sideshow Bob.

As of season 36, Sideshow Bob has appeared in more than 40 episodes, with speaking roles in 25 and 15 episodes centered on him. The latest episode centered on Bob, "Treehouse of Horror XXXIV", aired during the 35th season; his latest speaking appearance in the series was in "The Yellow Lotus" in the 36th season. Other episodes refer to Bob without featuring him, and his role goes beyond television into other Simpsons media. He appears in the Simpsons Comics and the 2007 video game The Simpsons Game; he also stars as the main antagonist in The Simpsons Ride at Universal Studios' theme parks. A lover of Gilbert and Sullivan operettas, Sideshow Bob is also known for his singing voice; several of Grammer's performances have been included in The Simpsons musical compilations.