The Arboreal Ratsnake (Gonyosoma oxycephalum) is a reptile in the Colubridae family of ratsnakes. It is also known as the Red-Tailed Green Ratsnake and the Red-Tailed Racer. 

The Arboreal Ratsnake is green and long, with wide smooth scales on its belly. It has smaller, smooth scales on its back. The top of its head may be green, yellow-green, or yellow. Some have a reddish-brown tail. It has a dark horizontal line through its eyes. Its tongue is black and often with brown or blue on the sides.