Robert Underdunk Terwilliger is a fictional character featured in The Simpsons, voiced by Kelsey Grammer. He was originally Krusty the Klown's silent sidekick Sideshow Bob, but has since become a villainous homicidal maniac. He is known for his abnormally large hair and feet and his inability to actually kill anyone, especially Bart.
It is possible that Sideshow Bob is based in part on the character of Dr. Terwilliker from The 5,000 Fingers of Dr. T. Not only are the surnames similar, but Sideshow Bob's accent and countenance bear a superficial resemblance to Hans Conried's performance, and both characters have a nemesis named Bart.
Bob never anticipated a career in show business. His younger brother Cecil (voiced by Grammer's Frasier co-star David Hyde Pierce) auditioned for the role of Krusty's sidekick (having wanted to since the age of five), but Krusty thought Bob's uptight demeanour would make him a better comic foil, and gave him the job instead.
As the years went on, the highly-educated Bob became increasingly angered at being overshadowed by Krusty's "dilapidated vaudeville antics", not to mention Krusty's continual abuse. Finally, he snapped and framed Krusty for armed robbery. He took over the show, making it more upmarket (for example, Krusty's catchphrase "Children, who do you love?" was replaced by the grammatically correct "Whom do you love?") introducing culture, singing Cole Porter, and reading the classics to his rapt young audience. Although the show earned critical raves - and boffo ratings - his reign was shortlived, as Bart exposed his plan and landed him in jail.
Since then, he has taken the position of Evil Genius in the series - a typical Sideshow Bob episode involves his being released from incarceration and acting out some cunning plan, which is foiled by Bart and (usually) Lisa. Frequently this plan involves killing someone: Krusty, Bart or everyone in Springfield. Bob has been eager to get revenge on Bart for foiling his schemes, but in "The Great Louse Detective", when he had the opportunity to kill Bart, he found himself unable to, as he had "grown accustomed to Bart's face".
Bob was briefly married to Selma (whom he also tried to kill, and in the process uttering perhaps his most famous line, "Soon I will kill you." while massaging her feet!), and was the Robert Mitchum/Robert de Niro character in the Cape Fear sendup episode. He is a staunch Republican, and was briefly mayor of Springfield. He can sing entire Gilbert and Sullivan operettas off the cuff. He also has a tendency to step on rakes, as evidenced in Cape Feare and Day of the Jackanapes.
Bob also has several tattoos, such as "Die Bart Die" (German, he claims, for "the Bart, the", which led to his being granted parole on the grounds that "no one who speaks German could be evil") on his chest and one resembling Bart's decapitated head on a skateboard on his back. The tattoos on Bob's fingers parody those of Robert Mitchum's character in the movie The Night of the Hunter (whose fingers are tattooed L-O-V-E and H-A-T-E), but, as Simpsons characters have only three fingers (besides the thumb), Bob's finger tattoos spell "L-U-V" and "H-Ā-T".
Bob's brother Cecil has harbored resentment for winning the role of Krusty's sidekick for many years, and during one of Bob's releases from prison, tried to frame him for embezzlement and sabotaging the Springfield Dam. Cecil's plan ended with mixed results: the sabotage did not destroy Springfield as expected, and both brothers took the blame for it. During the same episode it was revealed that Cecil attended Princeton University for four years (described as "Clown College" by Bob), whereas Bob had already been established as a proud graduate of Yale (like Mr. Burns). Like the two brothers, these Ivy League schools have a long-standing rivalry.
Bob's position as Krusty's sidekick is now taken by Sideshow Mel.
Sideshow Bob Episodes
- The Telltale Head: First appearance of Sideshow Bob as Krusty the Clown's much-abused sidekick. Bob only appears briefly on Bart's television and has no speaking lines. His hair is an afro.
- Krusty Gets Busted: Sideshow Bob's villainous debut. His hair has changed from an afro to a palm tree fronds hairdo. Krusty the Clown is framed for robbing the Kwik E Mart, and the entire town abandons him and embraces his replacement, the suave, sophisticated Sideshow Bob. However, Bart never loses hope in Krusty and is eventually able to unmask the identity of the real culprit... Sideshow Bob.
- Bart the Murderer: When Bart is thrown in jail, Sideshow Bob is shown as his buffed-up cellmate. However, Bob has no lines and does not do anything to Bart in this cameo.
- Black Widower: Selma begins dating her prison pen pal, whom the Simpsons discover is none other than Sideshow Bob. Sideshow Bob declares that he has been reformed by Selma's love, and eventually proposes to and marries her (all to the objection of Bart, who still believes Sideshow Bob is pure evil). On their honeymoon, it is revealed that Sideshow Bob only wants to kill Selma for her insurance money, but Bart manages to unravel his scheme and stop it at the last second, sending Sideshow Bob back to prison.
- Cape Feare: The Cape Fear parody. Bart receives a series of threatening letters written in blood, and soon afterwards Sideshow Bob is released from prison on parole. The Simpsons go into the witness protection program and move to Terror Lake, but Sideshow Bob follows them. After a few days of stalking, Sideshow Bob finally sneaks into the Simpson home to kill Bart. The two end up confronting each other on a small boat, and Bart manages to outwit Sideshow Bob by asking him to sing the entire score to the H.M.S. Pinafore as a last request, delaying Sideshow Bob long enough for the boat to crash, where a waiting Chief Wiggum arrests him.
- Lisa's First Word: In a flashback to 1984, Bob is seen briefly on Krusty's show. Strangely, his hair is rendered the same shade of teal as Sideshow Mel's by an inattentive artist error. He does not have any lines.
- Sideshow Bob Roberts: Sideshow Bob's outspoken and eloquent conservative viewpoints cause the town Republicans to parole him and get him to run for Mayor against Quimby, where he wins in a landslide (one of the arguments against Quimby being that he agreed with paroling known criminal Sideshow Bob). Sideshow Bob uses his new government power to make the Simpsons family suffer, scheduling their home for demolition and putting Bart in Kindergarten (though this actually makes Bart happier). Lisa discovers that Sideshow Bob won the election by registering dead people to vote for him. Lisa and Bart confront Sideshow Bob with the truth, and Sideshow Bob is arrested and sent back to jail.
- Sideshow Bob's Last Gleaming: Sideshow Bob's hatred of television prompts him to steal an atomic bomb from the Springfield Air Base, and he threatens to destroy all life in Springfield unless television is permanently cancelled. Krusty violates the cancellation, so Sideshow Bob attempts to detonate the bomb, but it turns out to be a dud ("best before November 1959"). Sideshow Bob then takes Bart as a hostage and goes off on a kamikaze mission aboard the Wright Brothers' plane to kill Krusty, but is foiled by the frailty of the Wright flyer.
- Brother from Another Series: Sideshow Bob is released from prison and enters into a work-release program headed by his brother Cecil. The program is a construction project working on the new Springfield Dam. Bart and Lisa believe Sideshow Bob is planning something terrible, and spy on his every move. The two run across evidence that suggests Sideshow Bob is planning to wipe out Springfield by sabotaging the dam. Eventually, it is revealed that Sideshow Bob really has reformed, and that it is his brother Cecil that is planning on destroying Springfield (to frame Bob as revenge for 'stealing' the position of Krusty's sidekick from him). Bart, Lisa, and Sideshow Bob team up to stop Cecil's plan, and Bart even saves Sideshow Bob's life when the dam begins to collapse, causing Sideshow Bob to promise to stop trying to kill him. However, Sideshow Bob ends up taking an equal share of the blame for Cecil's scheme, and both of them end up getting hauled off to jail by Wiggum.
- Day of the Jackanapes: Krusty the Clown's show is about to be cancelled by evil network executives, prompting Krusty to arrange for a final episode. Meanwhile, Sideshow Bob is enraged when he learns that Krusty has destroyed all evidence of his existence by taping over his old episodes (since Krusty had a love for Judge Judy and he didn't want to buy blank tapes), prompting him to enact yet another "kill Krusty" scheme, this time by hypnotizing Bart into becoming a suicide bomber and killing Krusty on the show. However, at the last minute, Krusty makes an on-air apology to Sideshow Bob for all the pain he's caused him, causing Sideshow Bob to have a change of heart. Sideshow Bob warns everybody that Bart is a bomb, prompting Krusty's monkey to swoop in and throw the bomb away (the only people hurt are the evil network executives, whose body parts merge into a T-1000 like monster). Sideshow Bob and Krusty finally resolve their differences, but Sideshow Bob is still scheduled to be decapitated for his crimes by Chief Wiggum (although the show cuts to the credits before we see the impact). He must have survived somehow, though, because he next appears in....
- The Great Louse Detective: A series of attempts on Homer's life prompts Chief Wiggum to consult Sideshow Bob as a Hannibal Lecter-style expert on the criminal mind. Sideshow Bob is eventually sent to live with the Simpsons to help reveal the killer's identity, with an electric shock device strapped to him to prevent him from causing trouble. In a final confrontation at Mardi Gras, Sideshow Bob saves Homer's life and the two confront the real killer... Frank Grimes Jr. In the end, Sideshow Bob sneaks into Bart's room and is about to kill him, but finds that he can't do it because he's "grown accustomed to Bart's face" a la My Fair Lady.
- A couch gag in "Mobile Homer" featured Bob seated on the couch with the family, disguised as Homer, and then revealing himself by whipping off a rubber mask and chasing Bart with a knife.
- Sideshow Bob will re-appear in a Season 17 episode, "The Italian Bob", as mayor of an Italian town that the family just happen to be visiting.