Gloydius monticola
Habitat
High mountains, 3,600–4,000 m
Range
North-western Yunnan, China (endemic)
Size
Largest female about 49.8 cm
Gloydius monticola, the Likiang pit viper, is a small, dark venomous pit viper endemic to the mountains of northern Yunnan, China, at 3,600–4,000 m. The type locality is Yaoshan near Lijiang. (The Reptile Database; Wikipedia, general species account)
The snout is rounded and the head is barely wider than the neck. It has 19 keeled dorsal scale rows at midbody and is black, dark brown or dark grey with almost no pattern. The only male examined in one study was 37.4 cm and the largest female 49.8 cm. (Wikipedia, general species account)