9. Heather Vomits A Fetus (And Claudia Eats It) - Silent Hill 3
The Silent Hill franchise admittedly prides itself on WTF nightmare fuel moments you'll wish you could permanently banish from your mind, but perhaps nothing has been more viscerally disgusting than the vomit-eating scene from the third game.
For context, protagonist Heather Mason learns during the game that she's being used as a vessel to give birth to the god worshipped by the cult residing in Silent Hill.
Given that the god's birth would result in Heather's death, she decides instead to forcefully purge the god-fetus by consuming the herb aglaophotis, which in occult lore wards off demonic entities.
And so, Heather promptly pukes up the crimson-red fetus - a nauseating feat in of itself - before the cult's high priestess Claudia decides that she will become the god's vessel instead, and goes about eating the damn fetus.
This leads to Claudia birthing the god and dying, with the player then battling the newborn creature in the game's final boss fight.
Silent Hill has never been afraid to push the envelope with objectionable content - remember Pyramid Head molesting two mannequins in the second game? - but it's also never been quite as primevally gross as one person yucking up a gestating fetus and somebody else devouring it.