For its incredibly bleak premise, In the Mouth of Madness has quite a few humorous moments.
- Trent fighting off the two orderlies at the beginning, kicking one in the balls. It helps that this becomes a Running Gag for the next few minutes.Trent: Look, I'm sorry about the balls, it was a lucky shot, that's all!
Dr. Wren: There's a guard with a pair of swollen testicles who swears you wanted out of here.
- And later:
- Trent declaring that he's not insane, and the inmates (one of them played by John Carpenter) doing likewise.Inmate #1: I'm not if he's not!
Inmate #2: Me neither!
- While in the bookstore, Trent runs into a typical Sutter Cane reader who's bleeding from the eyes and speaking in a Creepy Monotone. The fan says, "He sees you." Trent, ever the master of the Dull Surprise at this point in the film, simply responds, "Great. Tell him I say hi."
- While trying to escape from Hobbs End, an ax-wielding mutant runs up to Trent, stops for a second, and shouts, "Fuck you!"
- Mutant!Styles punching Trent in the face, and Trent punching back. And for that matter, her jingling Trent's keys while giggling and then swallowing them, much to his horror.
- Anything but That! — The Carpenters.
- After all, another Carpenter is responsible for everything that happens to Trent.
- For some reason, Trent has a bulb horn in his glove compartment, which he uses to wake up Styles for his own amusement. She isn't happy about it and throws an open bag of chips at him.Trent: Never, never, never throw chips at a driver.