Trivia: When Michael Jackson did a guest spot on the show he did his speaking lines himself but when it came to singing, a Michael Jackson sound alike or impersonator stepped in and sung the lyrics to the songs. The reason was based upon his record contract, which since he is so famous probably has a lot of stipulations when he lends out his voice.
Trivia: In this episode, Bart attends a Spinal Tap concert. Harry Shearer, who voices a number of characters on the show, played Tap bassist Derek Smalls in the film "This Is Spinal Tap."
Lisa's Pony - S3-E8
Trivia: At King Toot's music store, Homer is asked whether Lisa's Sax is a tenor or an alto. Actually, it's a baritone.
Tree House of Horror II: A Simpsons Halloween - S3-E7
Trivia: During the opening, the tombstones the camera passes by read 'Bambi's Mom,' 'Jim Morrison,' 'Cajun Cooking,' 'Walt Disney,' and one that says 'Lose Weight Now, Ask Me How.' (00:00:45)
Trivia: "John Jay Smith," credited as a guest star at the end of the episode, is in fact Michael Jackson, who starred as the man who thought he was Michael Jackson under a pseudonym. Michael is a massive fan of the show and also co-wrote the Simpsons' early hit, "Do the Bartman."
Tree House of Horror II: A Simpsons Halloween - S3-E7
Trivia: In the shot of the house during the opening credits, a group of trick-or-treaters walks past. This is the same group that goes trick-or-treating in "It's the Great Pumpkin, Charlie Brown" (1966).
Trivia: When the commercial is on about the lottery, the guy on the right is Lenny, just with a different color of hair. (00:01:35)
Trivia: In celebration of this episode's 25th anniversary, Homer Simpson was inducted into the Baseball Hall of Fame in Cooperstown, NY, complete with an exhibit highlighting the episode.
Answer: Willy referred to an encounter he believed he had with actual aliens, while Wiggum thought he was referring to the arcade game.