10 Genius In-Jokes In The Simpsons
4. Pixar's "A113" Easter Egg
"A113" is one of the most iconic inside jokes in animation history, created by alumni of California Institute of the Arts, primarily used by Disney and Pixar employees such as John Lasseter and Brad Bird to immortalise the classroom in which they learned the craft of character animation.
A113 has as a result appeared in Easter egg form in countless Disney/Pixar movies, video games, and TV shows, and this includes The Simpsons.
One of Pixar's most successful directors, Brad Bird (Ratatouille and both Incredibles films), got the ball rolling by including A113 as Krusty the Clown's prison number in "Krusty Gets Busted," and it also appeared as mugshot and prison uniform numbers for Sideshow Bob in the episodes "Cape Feare" and "Sideshow Bob's Last Gleaming."
Additionally it was also visible as Bart's mugshot number in the music video for the 1990 hit song "Do the Bartman."
Given that numerous Disney-Pixar personnel cut their teeth working on The Simpsons - including Wreck-it-Ralph and Zootopia director Rich Moore - there's quite the indelible connection forged between the two properties.
That A113 hasn't shown up more in The Simpsons is honestly pretty surprising, even restrained.