How to Identify the Ruby-Eyed Green Pit Viper (Identification Guide)

Key identifying features

The ruby-eyed green pit viper (Trimeresurus rubeus) is identified by its bright green coloration paired with distinctive reddish or ruby-toned eyes, a feature that gives the species its common name and sets it apart from many other green pit vipers with golden or greenish eyes.

Coloration & pattern

The body is a uniform vivid green, sometimes with a bluish tinge, and males often display a pale white or yellow stripe along the lower flank while females may lack this stripe or show it faintly. The tail is typically a contrasting reddish-brown. The belly is pale green to yellowish.

Head, eyes & scales

The head is triangular and distinct from the neck, with small granular scales on top. The eyes are a striking red or deep ruby color, a key diagnostic trait, with vertically elliptical pupils. Heat-sensing pits sit between eye and nostril. Body scales are keeled.

Size & body shape

This is a moderately slender pit viper, typically reaching 60 to 80 cm (about 24 to 31 inches), with a laterally compressed body adapted for climbing and perching on vegetation.

Range & habitat where you'll see it

The ruby-eyed green pit viper is found in parts of Vietnam and neighboring regions, inhabiting lowland and hill forests where it rests on low shrubs and branches, often near streams or forest edges.

How to tell it apart from look-alikes

The red or ruby eye color is the most reliable distinguishing feature separating this species from other similar green pit vipers, most of which have golden, greenish, or brownish eyes rather than red. Body pattern and size are otherwise broadly similar to related species in the same genus.