The common tree snake Dendrelaphis punctulata (also called green tree snake and Australian tree snake) is a slender, large-eyed, non-venomous, diurnal snake of many parts of Australia, especially in the northern and eastern coastal areas, and into Papua New Guinea. , 
This common snake is harmless, readily recognised as it is an agile snake with a very slender body and tail. The body colour varies from green to olive-green to black, sometimes even blue, frequently pale yellow on the throat and belly but other pale colours have been noted, blue flecks are present on the flank. Eyes are larger than in most snakes. Found in a variety of habitats ranging from rainforest to woodland to urban areas where it preys on fish, frogs and other small animals.
Common tree snakes live in a wide variety of habitats, including: bushland; well vegetated banks of rivers, creeks and streams; rainforest edges; eucalypt forests; heathland; and areas with trees, long grass, and lush vegetation—especially near water. ,  When near water they often look for long grass in locations where they are likely to find prey, blending in with grasses while watching for prey to come to nearby rocks or banks to bask or play. They will also enter nearby house gardens that have fountains or ponds surrounded by long grass or shrubs. They are active during the day, and rest at night in hollow trees, logs, foliage, or rock crevices. When resting they often are to be found in trees hence the name "tree snake".
Dendrelaphis punctulata is common in Australia's northern tropics and eastern Australia. It is also found from the Kimberley region (Western Australia) to Cape York and Torres Strait (Queensland), extending down the east coast into New South Wales, and north into Papua New Guinea., 
The common tree snake lays eggs — 5 to 12 elongated eggs per clutch. 
Although common tree snakes are essentially harmless to humans, they will defend themselves by producing a horrible odour, and may bite. Sometimes when approached, the snake inflates its body and neck to make itself seem larger, a tactic sometimes used to scare prey.  Generally, however, tree snakes in the wild will make a quick escape when they realize someone is watching them.