Whip scorpions, also known as vinegaroons (also spelled vinegarroons and vinegarones) are invertebrates in the arachnid family Thelyphonida. They are often called uropygids in the scientific community based on an alternative name for the order, Uropygi (which may then also include the order Schizomida). The name "whip scorpion" refers to their resemblance to true scorpions and possession of a whiplike tail. "Vinegaroon" is based on their ability when attacked to discharge an offensive liquid which contains acetic acid, producing a vinegar-like smell.
A whip scorpion (called a vinegaroon in the series) appeared in "Smelly".