Saw-scaled viper Echis carinatus carinatus. Found two of these at a plateau in my neighbourhood in North Goa yesterday, and another one today.
The saw-scaled viper is unfortunately a notorious member of the "big four" venomous snakes in India. It rarely makes its way into human habitation and does not bite unless disturbed. Yet its sheer abundance, tiny size, very effective camouflage, venom potency, and strong defensive behaviour result in lots of human casualties outdoors when they are accidentally encountered. The snake gets its name from its rough scales, which it rubs against each other to produce a loud rasping, 'sizzling' noise similar to hissing. The sound is also reminiscent of a rattlesnake .
Canon 760D, Canon 100mm Macro USM
Very minor crop to remove edge distractions
PS - Extreme caution should be exercised when photographing this species. It appears sluggish but is very agile and fast when striking, and makes several strikes in quick succession when stressed. I did not try to get it to move, all images were made around the snake's chosen spot. I backed off soon as I did not want to stress it once it began displaying.
Also, it is a good idea to use live view, as it allows one to always keep an eye directly on the animal.