Marge does not speak a word in this episode, but her voice actress is still credited. This was because Julie Kavner sat out of the episode completely in protest over the overuse of celebrity guest stars. This is the first time in the history of the series that one of the family members (excluding Maggie) does not have a single line.
There is a scene where The Red Hot Chili Peppers enter Moe's Tavern, and each of the members greets him. Flea, the last member in, shouts "HEY MOE" at the top of his lungs. During recording, Flea was not even in the booth at the time, but screamed so loudly that it was decided to use the take anyway.
Gabbo's name was undoubtedly inspired by The Great Gabbo (1929) which also dealt with a ventriloquist and his dummy, although in that film, the ventriloquist (played by Erich von Stroheim) was named Gabbo, not the dummy, who was called Otto.
One of the goals for the episode was to have an ex-President of the United States. They wrote "very respectful but cute" parts for each then-living ex-president (Richard Nixon, Gerald Ford, Jimmy Carter, and Ronald Reagan) at the time, but they all turned them down. Only the latter responded, sending a politely worded reply.