Protobothrops himalayanus

Protobothrops himalayanus is a rare lance-headed pit viper endemic to Asia, and like all pit vipers it is venomous. It is a large, thin, cylindrical snake with a dark brown head with red-brown streaks by the eyes, and an olive body and tail with black and brown bands. The eyes are varying shades of brown (Wikipedia, general species account).

The Reptile Database lists it from southern Tibet, Nepal, Bhutan and Sikkim. The only source opened is a short account, with nothing on size, habitat, diet or breeding, so none of those is stated. The entry is kept short on purpose.