|Airdate||December 26, 2000 (Christmas)|
The episode Crystals is a BrainPOP movie that aired on December 26, 2000.
Tim and Moby are walking in a cave and spot a letter addressed to Bob the ExLab Rat, who wrote a note asking Tim and Moby to answer the letter so he can do his experiment. Tim and Moby agree and talk about crystals. In the end, Moby scares Tim with a Cave Monster costume, but gets his mask stuck.