Xylophis stenorhynchus

Günther's mountain snake is a non-venomous snake found in the Western Ghats of India. The status of the Indian wood snake as a junior synonym of this species is tentative, since it is known only from one specimen collected more than a century ago, though there has been a tentative recent sighting from the Meghamalai Wildlife Sanctuary (Wikipedia, general species account).

The Reptile Database lists the Western Ghats of Tamil Nadu at about 1,200 m. The account used here gives no further detail.