Masticophis flagellum is a species of nonvenomous colubrid snakes commonly referred to as coachwhips or whip snakes, with seven recognized subspecies.
Coachwhips range throughout the southern United States from coast to coast. They are also found in the northern half of Mexico. Coachwhips are commonly found in open areas with sandy soil, open pine forests, old fields, prairies. They thrive in sandhill scrub and coastal dunes.
Coachwhips are thin-bodied snakes with small heads and large eyes with round pupils. They vary greatly in color, but most reflect a proper camouflage for their natural habitat. M. f. testaceus is typically a shade of light brown with darker brown flecking, but in the western area of Texas, where the soil color is a shade of pink, the coachwhips are also pink in color. M. f. piceus was given its common name because specimens frequently, but not always, have some red in their coloration. Coachwhip scales are patterned so at first glance, the snake appears braided. Subspecies can be difficult to distinguish in areas where their ranges overlap. Adult sizes of over 160 cm (63 in) are not uncommon.