Trimeresurus sumatranus

Trimeresurus sumatranus is a venomous pitviper species found in Thailand, Malaysia and Indonesia. Arboreal, its coloration is pale green with a red tail. Common names include Sumatran pitviper,Sumatran tree viper, and Sumatran pit viper.Trimeresurus sumatranus is a large heavy-bodied pitviper, with a prehensile tail. Adults may attain 1.6 metres (5 feet 3 inches) SVL (snout–vent length), with fangs over 10 mm (⅜ inch) long.

It is an arboreal species that is pale green in color with a red tail. The dorsal scales are edged with black, which may form crossbands in more mature specimens. There is a white or yellow stripe on each side along the first row of dorsal scales. Ventrally it is greenish or yellowish, and the ventral scales may be thinly edged with black.

Scalation includes 21 (23) rows of dorsal scales at midbody, 183–190/182–191 ventral scales in males/females, 57–66/55–64 subcaudal scales in males/females, and 8–10 supralabial scales.