[7] Aside from the usual variety that is black or has patches of black on a lighter background, color variations include the Texas rat snake, which is a brown-to-black variant, often with tinges of orange or red, that can be found in southern Oklahoma, Texas, and Louisiana.

They have adapted to a variety of habitats, including bayou, prairie, and rock outcrops, but they seem to have a particular preference for wooded areas, especially oak trees.

This association gave rise to one of its common names, pilot black snake, and the superstition that this nonvenomous species led the venomous ones to the den.

The record total length is 256.5 cm (8 ft 5 in),[10] making it (officially) the longest snake in North America.

[11][12][13] Juveniles are strongly patterned with brown blotches on a gray background (like miniature fox snakes: P. gloydi, P. ramspotti, and P. vulpinus).

Sometimes traces of the "obsolete" juvenile pattern are still discernible in the skin between the scales, especially when stretched after a heavy meal.

Utilizing its infamous agility and the great strength of its muscular coils, the black rat snake is sometimes able to overwhelm and kill formidable avian predators such as red-tailed hawks, great horned owls and red-shouldered hawks, though in many cases the bird is able to kill the snake and both combatants may even die.

[19][20] P. obsoletus is a constrictor, meaning it squeezes its prey to the point of cardiovascular collapse due to obstructive shock, coiling around small animals and tightening its grip until the prey can no longer circulate blood and dies of profound hypotension, before being eaten.

Several rat snake repelling methods have been offered to those putting up martin houses, but most are mixed in success.

However, Utiger et al. found that Elaphe is broadly construed as paraphyletic, and placed this species in the genus Pantherophis.

[27] The western rat snake is available captive-bred in the United States pet trade, and it has been bred for mutations such as leucistic, albino, and scaleless.

Opinions vary on the western rat snake's disposition, but captive-bred individuals are reported to be more docile than their wild counterparts.