An arboreal boa with a large bulky head, thin neck, stout body (can be over 2 inches in diameter) and strong prehensile tail. Pupils are vertically oriented like a cat. Color and pattern depends on locality but in general adults have brilliant green coloration with white to yellow underside and whitish or yellowish bands or blotches. Juveniles are a varied shade of yellow or red or a combination of those colors and green. As with all boas, they have spurs (anal claws) on both sides of the cloaca. Average adult size is between 4 and 6 feet, although those from the Amazon Basin average 7 to 9 feet and may reach as much as ten feet in length.
Rainforest of northern South America Amazon basin from Venezuela through Brazil to northern Bolivia.