Which monster scares you most, human/non-human

Broadly speaking, there are two main types of monsters that frightened me as a kid:

1. Human or humanoid monsters, from Karloff's Frankenstein's monster, to evil small humanoids like nasty leprechauns, the Mummy, humanoid/bipedal aliens, possessed or trance-programmed humans, humans taken over by non-human entities or parasites, headless ghosts seeking revenge, humans transformed into monsters deliberately or accidentally, vampires, werewolves, etc.
(I'm not counting purely human _psychological_ monsters like the Saw guy or Hannibal Lecter.)

2. Non-human monsters, from the Blob-types, to ghosts/phantoms/banshees, demons, non-humanoid aliens like Lovecraftian entities, the Alien Xenomorphs, the creatures from "Slither", the alien in Carpenter's The Thing and its "prequel", the locust-aliens from the two Quatermass films, the Fiends from Fiend without a Face, etc.
(I'm not counting dinosaurs, the Black Lagoon creature, sea monsters, King Kong for the biased and personal reason that they fascinated, rather than scared, me.)

How about you? Do you have a class of monsters that tend to frighten you more easily than other classes? Or genres of monster tales that push your fear button more than others ... ?