Willy Wonka's father (played by Christopher Lee) did not appear in Roald Dahl's book. The character was written specifically for the film to give Wonka some family history.

The many Oompa Loompas in Charlie and the Chocolate Factory are all played by the same man -Deep Roy. They used CGI to duplicate him. He would do a ton of different dance moves so when it's all put together, it would look like there were a bunch of different Oompa Loompas.

Charlie's father works in the Smilex Toothpaste factory. Smilex was the deadly poison gas used by the Joker to kill people in Batman, also directed by Tim Burton.

In the ribbon-cutting scene when Willy Wonka cuts the ribbon he turns around then his sleeve is covering his hand so all you can see are the scissor blades poking out. This is a reference to a previous Burton/Depp collabaration, "Edward Scissorhands."

When Wilbur Wonka throws the Halloween candy in the fire, some of the candies have the skeleton from "A Nightmare Before Christmas," another Tim Burton film.

In the scene with the young Willy Wonka eating a box of chocolates, he is writing down in a notebook a description of each chocolate he eats. When Roald Dahl was at boarding school there was a Cadbury's factory nearby that used the pupils as testers for their new chocolate, and they were asked to write down their comments in much the same way. This is mentioned in his book Boy.

After so many days of filming in the room where everything's edible, Johnny Depp and Tim Burton stated that the supposedly delicious chocolate river started to smell horrible, like rotten eggs.

The squirrels were all real and trained, but when they were all put on the set they began to fight. The squirrel scenes had to be done like the Oompa Loompa scenes, taping all the squirrels separately and pasting them together.

A camera lens worth over a half-million dollars was destroyed when it fell into the chocolate river during filming.

During the sequence in the "Television Room", there are two references to "2001 A Space Odyssey". First, the Oompa-Loompa is watching the scene where the primates are circling around the monolith. Second, as Willy Wonka starts the machine "Also Sprach Zarathustra" by Richard Strauss is played.

Wonka's cane is filled with Actual Wonka candy - Nerds candy, to be exact.

The squirrels in the movie are not CGI, but they're actually weird trained squirrels. There are obviously some parts with CGI, like when they carry Veruca into the pit, but they had about 40 trained squirrels. When they were finished, they gave most of the squirrels to people who wanted them as pets. The others went to zoos.

Five different squirrels were trained to push Mr. Salt into the trash hole.