The green tree python is characterized by a relatively slim body. The relatively long tail accounts for about 14% of the total length. The head is large and clearly defined from the neck. The snout is large and angular. The body is triangular in cross section with a visible spine. The species usually reaches a total length (including tail) of 150–180 cm (4.9–5.9 ft), but large females may reach 200 cm (6.6 ft).