Centipedes are predatory arthropods belonging to the class Chilopoda of the subphylum Myriapoda, an arthropod group which also includes Millipedes and other multi-legged creatures. Centipedes are elongated metameric creatures with one pair of legs per body segment. Centipedes are highly venomous, and often inject paralyzing venom; some species contain neurotoxic venom. Despite the name, centipedes can have a varying number of legs, ranging from 30 to 354. Centipedes always have an odd number of pairs of legs. Therefore, no centipede has exactly 100 legs. A key trait uniting this group is a pair of venom claws or forcipules formed from a modified first appendage. Centipedes are predominantly carnivorous.
Their size can range from a few millimetres in the smaller lithobiomorphs and geophilomorphs to about 30 cm (12 in) in the largest scolopendromorphs. Centipedes can be found in a wide variety of environments. They normally have a drab coloration combining shades of brown and red. Cavernicolous (cave-dwelling) and subterranean species may lack pigmentation, and many tropical scolopendromorphs have bright aposematic colors.