- Divided anal plate.
- 17 dorsal scale rows at midbody, with 13 scale rows found just in before the vent.
- Large eyes, in proportion to its head, which are useful for hunting active lizards and mammals.
- The dorsal background color can be highly variable, especially in Masticophis flagellum testaceus, ranging from black, red, yellow-tan, and even pink.
There are two subspecies of M. flagellum in Texas, each distinguished by its color pattern.
Some people suggest that the more darkly pigmented border of each dorsal scale (especially noticable on the tail) gives both subspecies a braided whip appearance.
One of the largest species in Texas, with a record individual measuring over 2.4 m (8 ft) in length, though the average adult size is 1.05-1.5 m (3.5-5 ft).
There are seven subspecies of Masticophis flagellum found throughout the southern half of the U.S. and the northern half of Mexico.
Although non-venomous, a captured coachwhip will not hesitate to bite quickly and repeatedly, leaving a series of shallow gashes in its aggressor\'s flesh. They are extremely quick and agile, moving across open ground and thick brush with equal effort and speed. Diurnal hunters, their large eyes help them see movement across their terrain. An observer may catch a glimpse of a coachwhip "periscoping" as the snake lifts the anterior third of its body perpendicular to the ground, allowing the snake to survey the landscape above for any potential prey movement. They feed on many different types of vertebrate prey, ranging from lizards and other snakes, to small cottontail rabbits and birds. Coachwhips will frequently climb trees to eat nestling birds or to escape predators. They are active from March to November in the warmer parts of its range.
Coachwhips mate in the spring, and females deposit clutches averaging 10 eggs in June and early July. The young hatch in 6 to 10 weeks, measuring 28-40.5 cm (11-16 in), and looking different than the adults. The juvenile pattern is an overall tan coloration with small brown crossbars down the length of the body. The belly is also pigmented with a double row of black spots, a belly pattern similar to the adult M. f. testaceus.
Although Masticophis f. testaceous is more commonly found in open areas such as grasslands and desert scrub, M. f. flagellum can occupy a wide range of habitats from swamps and creek bottoms to dry meadows.
The coachwhip is not a protected species in Texas and can be legally collected with a hunting license.
In Texas, the two subspecies of Masticophis flagellum are found throughout the state, with the two subspecies share a wide zone of overlap in the central portion of the state.