Trimeresurus labialis

The Nicobar bamboo pit viper is a venomous pit viper endemic to the Nicobar Islands of India. Males may attain a total length of 42 cm, with a tail of 8 cm, and females 44 cm, with a tail of 7 cm. It is brown above, light or dark, with or without darker spots or crossbars, and may have a light streak on each side of the head from the snout under the eye to the neck. Underneath it is also brown (Wikipedia, general species account).

The back scales are smooth, usually in 23 rows at midbody. The account used here gives no information on habitat, diet or breeding.