* The ''bodachs'' from the Odd Thomas books. The idea that these shadowy creatures appear at scenes of violence and death is bad enough, but then you learn that they show up because watching people in torment is ''exciting''. Not only is someone coming after you with a chainsaw, but there are ''things'' watching it happen and cheering it on because they feed off your fear. Yeesh.
** The way they're depicted in the second graphic novel. They look a little like dogs, in the same way that a rotting corpse looks a little like the person it once belonged to.
** In the movie, they just seem to get more and more monstrous as the film goes on.
** That and the fact that as soon as they find out you can actually see them, they'll kill you.
* The Senoculus in "Deeply Odd" which takes Odd's form with some disturbing differences like a SlasherSmile revealing razor teeth. It is invincible, supernaturally strong, and wants to suck out your soul... by kissing its victim.
* Also, the EldritchAbomination in "Deeply Odd" to which [[spoiler: Odd's SpiritAdvisor Creator/AlfredHitchcock]] advises Odd to simply run and not look back lest he go insane from the sight.