Tailless Whipscorpions (Paraphrynus mexicanus) are nocturnal arachnids found here in southern Arizona. They use their long, delicate, whip-like, antenniform front legs as sensory organs to search for prey in the dark.
These arachnids look horrifying, but they are really quite harmless unless you happen to be a cockroach. They have a peculiar affinity for my garage (otherwise known as the invertebrate zoo), and I see them fairly frequently, especially on warm summer nights.
Despite their common name, Tailless Whipscorpions are not scorpions and have no stingers. They do appear to possess large, scorpion-like claws, but these are their large, spiny pedipalps that they use to capture their insect prey.
Despite being 8-legged arachnids, Tailless Whipscorpions are not spiders either. They are in Class Arachnida along with spiders and scorpions, but they are in their own order, Order Amblypygi and in the Tailless Whipscorpion Family (Phrynidae). Tailless Whipscorpions are primarily tropical and subtropical species, and despite their creepy looks, they are considered to be beneficial because they are nonvenomous and help control insect pests like cockroaches.