king snake, name for a number of species of the genus Lampropeltis, nonvenomous, egg-laying, constricting snakes of North America which show much variation in color and markings. The common king snake, or chain snake (Lampropeltis getulus), of the E United States is usually about 3 to 5 ft (90-150 cm) long and black or brown with yellow and white rings or bands that form a chainlike pattern. It eats rodents, birds, and snakes. It is immune to the venom of the rattlesnake and the copperhead, which it kills by constriction. The scarlet king snake (L. doliata) has a pattern of black, red, and yellow bands similar to that of the unrelated coral snake. Other less brightly marked varieties of the same species are called milk snakes, because they are reputed by legend to milk cows. King snakes are valuable destroyers of rodents. They are classified in the phylum Chordata, subphylum Vertebrata, class Reptilia, order Squamata, family Colubridae.

Any of seven species of snake (genus Lampropeltis, family Colubridae) found in numerous habitats from southeastern Canada to Ecuador. They kill by constriction; named for their practice of eating other snakes, they also take small mammals, amphibians, birds, and birds' eggs. They are mainly terrestrial and relatively slow-moving. Strikingly marked and smooth-scaled, they have a small head and are usually less than 4 ft (1.2 m) long, though some specimens may approach 7 ft (2 m). The common king snake, found throughout the U.S. and in northern Mexico, is usually black or dark brown, variously blotched, ringed, or speckled with yellow or white.

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