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Mr. Bill is a clay figurine star of a parody of children's clay animation shows created by Walter Williams in 1974. "The Mr. Bill Show" got its start on Saturday Night Live as a series of Super 8 films sent in in response to the show's request for home movies during the first season. Mr. Bill's first appearance occurred on the February 28, 1976, episode. After five submitted films, Williams became a full-time writer for the show in 1978 and wrote more than 20 sketches based on Mr. Bill.

Each Mr. Bill episode started innocently but quickly turned dangerous for Mr. Bill and his dog Spot. He would suffer various indignities inflicted by "Mr. Hands", a man seen only as a pair of hands (originally performed by Vance DeGeneres).

Sometimes the abuse came from Sluggo, another clay character. The violence inevitably escalated, generally ending with Mr. Bill being crushed or dismembered while squealing "Ohhhh noooooooooooooo!" in a high-pitched voice. The concept for Mr. Hands came from Williams' observation that children's cartoons in the '70s were so static, he expected the artist's hands to enter the screen at any moment and physically start moving the drawings around.

Initial Saturday Night Live sketches featuring Mr. Bill were self-contained episodes with no direct continuity, with the earliest installments featuring higher-pitched character voices. After Walter Williams joined SNL's writing staff in 1978, Mr. Bill formally moved to New York at the start of the season. Later sketches saw Mr. Bill become aware of Mr. Hands and Sluggo's mistreatment, with the 1979–80 season harboring an extended story arc where Mr. Bill lost his home, sought psychiatric help, attempted to get Mr. Hands and Sluggo arrested, and was ultimately thrown into prison.

Williams left Saturday Night Live after that season, but Mr. Bill returned for a Christmas short film in December 1980, as well as the sixth-season finale, where guest Chevy Chase found Mr. Bill in a garbage can. The last Mr. Bill sketch on SNL aired early in the 1981–1982 season, where Mr. Bill moved to Los Angeles. After SNL, Mr. Bill has appeared on numerous other television programs and advertisements, including regular new sketches on the USA Network series Night Flight in the 1980s and the Fox Family Channel series Ohh Nooo! Mr. Bill Presents in the 1990s.