At first, it just looks like a worm. But when you peek closer, it slithers like a snake. It sticks its tongue out like a snake. It creeps you out like a snake. Discovered under a rock in 2006 in Barbados, this thread snake is as thin as spaghetti and smaller than any of the 3,100 other known snake species. Researchers believe it is the smallest a snake can evolve to be.