brown tree snake 

This snake is not considered dangerous to humans although the toxicity of their bite will have a different reaction on each individual, first aid is always recommended. 

Slender body with a distinct broad head and large vertical pupil eyes, reddish brown to dark brown colour.  Growing up to 2M in length. Mid body scales in 19-23 rows.

 Arboreal species, living in forests, gorges, grasslands, swamps, and mangroves. In urban areas will commonly be encountered in roof voids and backyards.

Feeds mainly on small mammals and birds but will also consume reptiles and frogs. 

Northern and eastern Australia from Kimberley, WA, to Wollongong, NSW. Also lives in Papua New Guinea , Indonesia and introduced to Guam.