whip scorpion
A group of arachnids belonging to the order of Uropygi. They possess scorpion-like pincers, a long whip-like tail, eight legs; six legs for walking and their front most two legs for feelers. They do no possess venom glands, but do have glands near the rear of their abdomen that produce a combination of acids which they can spray when they're bothered.
Their naming comes from their similarity to true scorpions, but they're more closely related to spiders.
