The arana is a master of disguise. Its body and its two pairs of jointed limbs evolve to resemble a tree stump to the extent of growing tufts of hair resembling grass and harboring mushrooms and moss on its back. Its carapace and legs are protected by sharp spine-like excrescences to deter predators. It has small eyes on fleshy stems sprouting from the top of the head, and powerful lower tusk-like mandibles with which it will attack if threatened. This herbivore can be observed scuttling along fast on the tips of its horny toes in the forest and desert regions.