Snakes that spend the majority of their life living off the ground in trees and brush are arboreal. These snakes are generally long, slender and some variant of green to help them to camouflage against the green backdrop of the trees. In addition arboreal snakes have specific traits that allow them to be more efficient in the trees. Examples include:

• They are light bodied which allows the trees and brush to support their weight
• Some have longer fangs making it easier to catch and hold birds out of the air as they fly by
• They have more acute vision than their ground-dwelling and burrowing cousins

The photo shows a Rough Green snake, a classic example of an arboreal snake. Slender, light and green.