I think Tusk has to be right up there. Justin Long's character goes to interview an old seafarer who ends up drugging him, imprisoning him and surgically turning him into a walrus.

I saw Kevin Smith live a while back, and apparently the movie was based on some random Craig's List ad him and his friends saw, where someone wanted to pay a person to come and dress up in a walrus suit... and they figured it was some psycho who wanted to sew you into the suit and keep you as a pet.