The Simpsons has been a pop culture institution for over thirty years. Being on the show can be seen as the ultimate seal of approval on someone's celebrity status, with many performers embracing their off-kilter guest spots. In many cases, celebrities will even poke fun at themselves in cameos on the show, but according to series creator Matt Groening, comedian Don Rickles -- a famous stand-up comedian who eventually played Mr. Potato-Head in Toy Story -- was offended at a proposed guest spot.
Rickles guest spot would have provided the B-plot for the Season 4 episode "New Kid on the Block," which was written by then-series writer Conan O'Brien. The episode was largely focused on the Simpsons gaining a new neighbor in the form of Ruth Powers and her teenage daughter Laura -- who Bart developed a crush on. It's a sweet but somewhat forgettable episode from the Golden Age of the show.
The B-Story, intended as more of a comic routine than the genuine emotional arc afforded to Bart, focused on Homer and Marge visiting the all-you-can eat seafood buffet at the Frying Dutchman. When the Sea Captain orders Homer to vacate the building before he's full, Homer ends up hiring Lionel Hutz to defend his right to eat as much as he wants in court.
Within the context of the series itself, the secondary plot of "New Kids on the Block" is perhaps most important for being the formal introduction of the Sea Captain, who would go on to become a reoccurring side character in Springfield, but the original intention behind the plotline was much different, according to the commentary for the episode included on the DVD release of Season 4.
This B-plot would have instead focused on Homer and Marge attending a Don Rickles comedy show. Famous for his heckling of the audience at his sets, Rickles would have found a boisterous fan in Homer -- at least until his jokes turned toward Homer, at which point their feud would have eventually gone to court. Fans of Rickle's comedy, O'Brien and the rest of the staff used snippets from Rickles' comedy albums in the script.
However, when they approached Rickles about appearing in the show, the comedian was reportedly offended by the suggested plotline. Infuriated that the episode portrayed him as a "mean guy," Rickles turned down the part. On top of that, Groening revealed during the commentary that not long after Rickles and Groening both found themselves at a publicity event -- and Rickles confronted Groening about the entire event. He even accused The Simpsons writing staff of recording his comedy shows illegally to gain material for the episode, unaware that they, as fans of his work, simply bought copies of his comedy album. A future episode even may have quietly referenced this, with a clear pastiche of Mr. Potato-Head appearing as part of a Pixar-expy who threatened Lisa in Season 22's "Angry Dad: The Movie."
It's a fascinating footnote in the history of The Simpsons, partly because very few celebrities have responded with outright hostilities toward the show. While some celebrities simply turn down the chance, other performers, like Prince, actively worked on episodes that never saw the light of day. Meanwhile, Rickles stands out for having a reportedly angry response to their attempts to poke fun at the comedy icon. In a strange twist of fate, the intended gag of the B-plot (Homer's inability to take a joke) seemed to have carried over into real life behind-the-scenes of the episode.