The monkey slug caterpillar one oddly shaped creature.
Sometimes mistaken for a hairy spider, sometimes for moldy leaf litter, this larvae has six hairy "arms" that curl out from each side of its body. It has extremely shortened legs, and the prolegs are suction cups, which create the appearance of a slug when you look at it belly-side up. Indeed, its miniscule legs and oddly long "arms" make it weirdly mesmirizing to watch, and you can see in the video below how it could be mistaken for a strange tarantula at first glance:
Not creepy enough? Okay, well there's also this video:
While it looks like a nightmare creature that should be avoided, the monkey slug caterpillar is relatively harmless. Thanks to David L. Wagner, who tested it himself, the hairs of this species of caterpillar don't sting. That said, it may still cause a reaction for some sensitive people, so if you come across a monkey slug, it's best to avoid touching it.
Contrary to the happy metamorphoses made by story-time creatures like ugly ducklings and hungry caterpillars, the monkey slug transforms into ... the hag moth. (Poor thing just has to be content with drawing the short straw for attractiveness no matter its stage of life.)
The species is found from Maine and Quebec south to Florida, and west to Nebraska, Arkansas and Mississippi.