...toxic farts, Jonesy's warehouse, and everything. Yes, I did say toxic farts. That wasn't the sound of them that everyone was wincing at. According to the book, they smelled like something similar to methane and ammonia and were REALLY strong.
The only real departure from the book was Mr. Grey taking any kind of physical form after his head exploded in front of Jonesy. Duddits never transformed at the end, either, but he did die. It is kind of hard to put a mental assault on film, though, so I guess they had to do something :-)
I also thought Beaver would have had longer hair. Jason Lee did do a good job with the character, though. All of the acting was good.