Scorpions are predatory arthropod animals of the order Scorpiones within the class Arachnida. They have eight legs and are easily recognized by the pair of grasping claws and the narrow, segmented tail, often carried in a characteristic forward curve over the back, ending with a venomous stinger. Scorpions range in size from 9 mm (Typhlochactas mitchelli) to 21 cm (Hadogenes troglodytes).
Scorpions are found widely distributed over all continents, except Antarctica, in a variety of terrestrial habitats except the high latitude tundra. Scorpions number about 1,752 described species, with 13 extant families recognised to date. The taxonomy has undergone changes and is likely to change further, as a number of genetic studies are bringing forth new information.