They feed almost exclusively on crabs, which they tear into bite-sized pieces by pulling them through their coils, in contrast to most other snakes which swallow their prey whole.
Frontal a little longer than broad, shorter than its distance from the end of the snout, or than the parietals; loreal slightly longer than deep, a little smaller than the nasal; one pre- and two post-oculars; temporals 1+2; upper labials 8, fourth entering the eye; 4 lower labials in contact with the anterior chin-shields, which are much larger than the posterior. Scales in 17 rows. Ventrals 146–158; anal divided; subcaudals 31–34. Uniform dark olive above; three outer rows of scales whitish; upper lip white, rostral dark olive; ventrals and subcaudals whitish, with dark edges.
Total length 41 cm (16 inches); tail 5 cm (2 inches).
India, Myanmar (= Burma), Sri Lanka, Thailand, Philippine Islands (?), Bangladesh, west Malaysia, and Singapore