Liasis fuscus

Adults average about 6–8 feet (2+ meters) in length, but may reach 10 feet (3.0 meters). Robustly built, it has a long head that is slightly distinct from the neck. The anterior supralabials have thermosensitive pits. Scalation includes a pair of undivided parietal scales and a single loreal scale on either side of the head. On the body, the dorsal scales number 45-55 at midbody, the ventral scales 270-300, the anal scale is single, with 60-90 paired subcaudal scales. The color pattern consists of a uniform, iridescent dark blackish brown dorsal color. The belly is a dull to bright yellow that includes the first few rows of dorsal scales. The throat is cream colored, while the upper labials are light gray-brown with dark brown or black spots.

They are found in Australia in the Kimberley district of northern Western Australia from around Broome east through Northern Territory at least as far south as Mataranka to the coast of central Queensland to near Mackay. Also found in the Sir Charles Hardy Islands, on Cornwallis Island in the Torres Strait, and in Papua New Guinea, Western District, in the lower Fly River region at least as far inland as Lake Daviumbo. It can also be found in the southern part of Papuan province of Indonesia. The type locality given is "Port Bowen" (Port Clinton, Queensland, Australia). The highest population density is reached on the Adelaide River floodplains in the Northern Territory.

Despite its common name, many individuals are found far from water for most of the year. They are usually nocturnal, seeking shelter during the day in hollow logs, in riverbank dens, and in vegetation. When surprised, most attempt to flee into any available water.