Thamnophis marcianus

The checkered garter snake (Thamnophis marcianus) is a species of garter snake in the subfamily Natricinae of the family Colubridae. The species is endemic to the southwestern United States, Mexico, and Central America. The specific epithet, marcianus, is in honor of American Brigadier General Randolph B. Marcy, who led surveying expeditions to the frontier areas in the mid 19th century. The checkered garter snake is typically greenish in color, with a distinct, black checkerboard pattern down its back. It is capable of growing to a total length (including tail) of 42 inches (107 cm), but is usually 18 to 24 inches (46 to 61 cm). The preferred habitats of T. marcianus are desert and grassland, usually close to water. The diet of T. marcianus includes small frogs, toads, small fish, and earthworms. If kept as a pet, it can be trained on live or freeze-thawed mice, but even so, it is fussy eater and can suddenly start to refuse mice at any point. T. marcianus will strike and bite if provoked. It will also release a foul-smelling liquid from its cloaca onto attackers. T. marcianus has been found to have mild venom. Two subspecies of T. marcianus are recognized as being valid, including the nominotypical subspecies.