Size: 870 mm SVL, 1235 mm TL, may exceed 2135 mm TL, hatchlings 255 mm. Identification: Adults a uniform olive green with some, but not all scales keeled in 21 or 23 rows at mid-body reduced to 15 rows posteriorly, and upper labials 4-5-6 in the orbit. Young (<495 mm TL) have crescent-shaped blotches that form cross bands on the dorsum. Rostral visible from above; nasals single; loreal single; one preocular; two postoculars; seven upper labials,10−11 lower labials; ventrals 193−203; cloacal single; divided subcaudals 156−181 in males 125−126 in females; dorsal scales smooth with apical pits. Perhaps most easily confused with snakes of the genus Chironius which have 10 or 12 dorsal scales at mid-body; and with Spilotes sulphureus which has a black and yellow dorsum and upper labials 4−5 on the orbit. Ranges from Columbia to the Guianas, including Trinidad, and southward into the Amazon basin. An arboreal snake of forest and forest-edge habitats. Diurnal and crepuscular. Diet: Actively forages for nestling birds and eggs; probably a specialized nest predator; but will also prey on lizards and mammals. Defense: Cryptic behavior includes kinking its body into a shape that resembles a liana to avoid detection; behavior includes inflate its forebody, gape its mouth, actively striking, and vibrating its tail when disturbed.