Several species of these fuzzy-looking caterpillars, of the genus Megalopyge, can be found in the Southern United States, Mexico and parts of South America. And they can grow quite large.
Oh, and about that cute fuzziness? Nope. They're actually covered in poisonous barbs that can cause humans and other animals excruciating pain along with headache, nausea, vomiting, trouble breathing and even shock. One species, Megalopyge opercularis, has the dubious honor of being the most poisonous caterpillar in the United States.