Trivia: When Quasimodo is singing a few minutes into the film, he is standing above the town street where people are walking around, doing business. If you look closely to the lower right of the scene, you can see Belle from "Beauty and the Beast" reading a book in her blue dress, walking.
Trivia: In this movie, Robin Williams (the voice of the Genie again) seems to spoof some of his real-life roles. I haven't seen all of them, but Mrs. Doubtfire is certainly included.
Trivia: While Centipede is on the skeleton ship, he enters into a room where the Skeleton Captain is laying on a compass, and Centipede murmurs, "A Skelington?" This was probably a reference to a previous Tim Burton character, Jack Skelington in "The Nightmare Before Christmas". The fact that the Captain greatly resembles Jack supports this theory.