This actually came to mind, specifically when he was talking to the still-alive decapitated head of his friend.Antz, the part with the war against the termites.
I was subjected to a gauntlet of classics from my babysitter who was really into horror and because we were boys trying to seem tough and cool we pressured each other to survive them. Exorcist, It, Hellraiser, Night of the Living Dead, you name it. None of them bothered me as much as the original Texas Chainsaw Massacre did. That was my 'chickened out' movie. That first kill and appearance of Leatherface at the doorway scared the piss out of me and the general atmosphere of the movie before that scene was making me feel sick already. Rewatched it a few years back and I don't blame my child self.
Honorable mention to the shaving scene from Cabin Fever.