Ovophis zhaoermii

Ovophis zhaoermii, the Guanyinshan mountain pitviper, is a venomous mountain pit viper endemic to Yunnan, China. It is brownish-black to reddish-brown, with no pattern on the head, rectangular black blotches along the body and white spots on the tail. (The Reptile Database; Wikipedia, general species account)

Its diet is unknown, but an Ovophis snake, possibly this species, was seen with an adult male Ailao moustache toad in its jaws. (Wikipedia, general species account)