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Nightmare Fuel: Hogfather
Jonathan Teatime. He's creepy enough when he's just terrifying Assassins and nailing dogs to the ceiling with that cheerful Psychopathic Manchild smile, but as the plot goes on he starts manifesting very subtle supernatural powers...
Hogfather is also notable for thematic exploration of normal Nightmare Fuel — as an Eldritch Location starts fighting back against Teatime's crew, more and more of them start to see manifestations of their irrational childhood fears. Except that those fears are now real and quite capable of killing them.
Possibly the most horrifying of these nightmares is the Scissor Man, who could be easily described as a Velociraptor made out of scissors.