Bogertophis subocularis subocularis - Trans-Pecos Ratsnake
It has a row of small scales (suboculars) between the lower border of the eye and the upper labials. This is a beautiful snake, yellow to tan dorsally with a series of black or dark brown H-shaped markings. The eyes are large and prominent, light-colored with contrasting round black pupils. The tongue is pink. Dorsal scales in 31-35 rows. Ventrals 260-277; subcaudals 69-79.
It is found in the Mexican state of Coahuila, and its range extends northward into Texas and New Mexico.
The Trans-Pecos rat snake's habitat consists of desert flats and brushy slopes, and rocky outcrops where they nest and feed on small vertebrates. A nocturnal species, it is uncommon and rarely-seen in the wild, save on warm summer nights during the breeding season. Nicknamed "subocs" by enthusiasts, they are unaggressive when approached, even passive, and are easily raised in captivity.
Males are larger than females as adults. Adult females reach between 3½ to 4½ feet (1.1-1.4 m) long; whereas males grow up to 5 feet (1.5 m) or more.
Their breeding season runs through May and June, while egg-laying begins in July and ends by September. At nearly three months, their incubation period is lengthy for a snake, at the end of which a clutch of anywhere from three to 11 snakes of 28–33 cm hatch. As they are born during winter, the hatchlings may remain hidden underground for several months before venturing outside.