Ahaetulla farnsworthi

Farnsworth's vine snake (Ahaetulla farnsworthi) is a tree snake found only in the central Western Ghats of India. For a long time, it was lumped together with *A. nasuta*, a species now understood to live exclusively in Sri Lanka. A 2020 investigation revealed that *A. nasuta* actually represents a species complex, with *A. farnsworthi* being one of several distinct forms—alongside *A. borealis*, *A. isabellina*, and *A. malabarica*. The snake's name honors Professor Farnsworth, a character from the animated series *Futurama*, chosen as a nod to his fictional work reviving extinct barking snakes.

The body is extremely slender, with adults reaching up to one meter in total length. Its back is a uniform bright to olive green. The snout, lower jaw scales, and belly are yellowish to light green at midbody, with a yellow or white stripe running along the notched belly scales. A slight color change appears on the scale in front of the eye. The skin between the scales is white, marked with black and white bars that converge toward the front; toward the rear, this white gives way to reddish brown. The eyes are golden yellow with black speckles, and these speckles cluster at both ends of the horizontal pupil. A faint discoloration rings the pupil. The tail and its underside scales are green.

Scale counts vary within the species: 167 to 177 notched belly scales with keels; 141 to 165 divided scales under the tail in males, 126 to 150 in females; the anal scale is divided. The body has 13, 15, or 16 rows of smooth, slanted scales at the neck, reducing to 15 then 13 or 11 rows at midbody. There are 7 or 8 upper lip scales, with the fifth touching the eye; the fourth is split. No loreal scale is present. Lower lip scales number 8 to 10. There are 1 or 2 pre-suboculars, a single pre-ocular on each side, 2 post-oculars, no sub-oculars, and 1+2, 2+2, or 2+3 temporal scales.

This snake lives only in Karnataka, from Coorg north to the Agumbe-Kodachadri range. In Coorg, it may share territory with *A. malabarica*, but rivers largely keep them apart. Near its northern limit, it meets *A. borealis*, likely separated by the Sharavathi River basin. Its habitat is mid-elevation tropical rainforest in the central Western Ghats, between 500 and 850 meters above sea level.