In the Dungeons and Dragons universe, Mindlfayers are a race of brain-eating Cthulhus that serve giant floating brains in underground caves. They traditionally have octopus faces and I think they're supposed to physically eat brains? Like with a beak and stuff? But since they're essentially Lovecraft monsters, I thought it would be more fitting for them to just turn people insane by being super scary and feed of their psychic energy. The end.