Krusty asks, "Chaim Potok! Who is he, some kind of Klingon?" In reality, Chaim Potok was a famous Jewish-American writer.
Lisa breaks the fourth wall by consulting the real-world reference book "The Simpsons: A Complete Guide to Our Favorite Family" - which provides detailed synopses and trivia for each episode of the first eight seasons of the show - to look up the last time Santa's Little Helper sired puppies (Two Dozen and One Greyhounds (1995)).
The only time as of August 2021, Mr. T has voiced himself in the series. Even though the character has appeared other times he was voiced by Simpsons cast member Hank Azaria.
Homer and Marge wouldn't need to wait in line for the bathroom as they have their own bathroom in their bedroom.