Protobothrops kaulbacki

The specific name, kaulbacki, is in honor of British explorer Ronald Kaulback.^[3][6][7][8]

Adult males of P. kaulbacki may attain a total length of 134 cm (53 in), which includes a tail 22.5 cm (8.9 in) long. Females may grow longer: maximum total length 141 cm (56 in), tail 23 cm (9.1 in). Dorsally, it is green, with a vertebral series of dark angular spots, which may be joined to form a zigzag stripe. The top of the head is black with yellow stripes. Ventrally, except for the whitish throat area, it is gray with large squarish or crescent-shaped yellow spots.^[9] Scalation includes 25 rows of dorsal scales at midbody, 201–212 ventral scales, 66–78 subcaudal scales, and 8 supralabial scales of which the third is the largest.^[4]

P. kaulbacki had originally been known only from the type locality, which is "Pangnamdim, north of the Triangle, Upper Burma" (Myanmar).^[2] In 2005 it was reported also from Tibet (China).^[1][10] It also occurs in Arunachal Pradesh (NE India).^[3]

The preferred natural habitats of P. kaulbacki are forest, shrubland, and grassland, at altitudes of 1,015–1,066 m (3,330–3,497 ft).^[1]

P. kaulbacki is oviparous. The adult female lays a clutch of 6–32 eggs in a hole in the ground, and then remains with the eggs to guard them. Eggs measure 48–53 mm x 26–27 mm (about 2 in x 1 in). Each hatchling is 26–27 cm (about 10½ inches) in total length.^[9]

P. kaulbacki is terrestrial^[1] and partly arboreal.^[11]