FACT:
A uropygid, commonly known as a Whip Scorpion, is an invertebrate animal belonging to the former order "Uropygi" in the class Arachnida, in the subphylum Chelicerata of the phylum Arthropoda. They are also known as the vinegarone or vinegaroon (in Spanish, vinagrillo) because when agitated they can spray a vinegar-like mist.
Whip scorpions range from 25 to 85 mm in length; the largest species, of the genus Mastigoproctus, reaching 85 mm.
Like the related orders Schizomida, Amblypygi, and Solifugae, the uropygids use only six legs for walking, having modified their first two legs to serve as antennae-like sensory organs. Many species also have very large scorpion-like pedipalps (pincers). They have one pair of eyes at the front of the cephalothorax and three on each side of the head. Whip scorpions have no poison glands, but they do have glands near the rear of their abdomen that can spray a combination of acetic acid and octanoic acid when they are bothered. The acetic acid gives this spray a vinegar-like smell, giving rise to the common name vinegaroon. Other species spray formic acid or chlorine.