A motorcyclist decides to stop and pee by the side of the road... but he arouses the anger of Bigfoot, who seizes on the most convenient part of his anatomy, in this godawful, NSFW sequence from Night Of The Demon.
I love how the head Sasquatch researcher tells his team this penile mutilation story by the campfire, then says, "Let's get some sleep." Riiiight.
The 1980 version of Night Of The Demon is a truly horrible "achievement," including the finale, where Bigfoot rips out a guy's intestines and then uses them to whip the guy's friends. And the girl scout murders. Most of all, there's a long (way too long) sequence where the researchers into Bigfoot hypnotize a woman named Crazy Wanda, so she can tell all about when she was 15 years old and Bigfoot fell in love with her. This led to Bigfoot assaulting her in her front yard, right in front of her religious fundamentalist father. Crazy Wanda gets pregnant with Bigfoot's mutant offspring, and her Christian dad forces her to have a chemically induced abortion - so she lights her dad on fire. As I said, this whole "Crazy Wanda flashback" sequence occupies about ten minutes of the movie, and gets progressively more and more awful.
It's hard to believe this filth is on Youtube! (Hypnosis and "Crazy Wanda" flashback starts at 0:44, but be warned - it's not for the squeamish or anyone who's just eaten. Or, really, for anybody who's got even an iota of taste or standards.)