The body of the Green Tree Python is laterally compressed with a large head that seems disproportionate to the width of the body. The tail is prehensile. They have greatly elongated foreteeth. The color of the adults is bright to dull emerald green above with a complete or broken series of white or yellow scales along the vertebral line and a few scattered white scales on the sides. A series of short, light blue bars extend out from the vertebral line. The belly is cream to light yellow. There are heat sensitive facial pits within the scales bordering the upper lip. The juveniles are a bright lemon-yellow, gold or orange to brick red, often with a dark purplish-brown white-centered streak through the eye and a vertebral stripe of the same color with short bars of brown extending from the vertebral line. Length can reach 6.5 feet, but rarely exceeds 1/2 that.