With adults reaching over 4m in length, this is Australia's second largest snake species. Its high midbody dorsal scale count, 61-72, makes the skin look smoother than that of other pythons. The number of ventral scales is 355-377. The color pattern is a uniform chocolate brown to olive green while the belly is usually cream colored.

Unfortunately, this species is occasionally confused with the venomous king brown snake, Pseudechis australis, and killed as a consequence.

Found in Australia in Western Australia, Northern Territory and Queensland. The type locality given is "North Australia; Port Essington" (Northern Territory, Australia). Occurs rocky areas, gorges and especially rocky areas near sources of water. Typically, shelter is sought in caves and rock crevices, but individuals have also been found in hollow logs and in burrows under rocks.

The diet consists of birds, mammals and other reptiles, including rock-wallabies, fruit bats, ducks and spinifex pigeons. They prefer to lie in wait next to animal trails to ambush their prey. Alternatively, they are strong swimmers and also hunt in waterholes, striking at prey from under the water.

Ovoviviparous, Mating activity starts in May and continue through until mid-July. When successful, this is followed by a gestation period of 81–85 days, after which the females lay 12-40 eggs in late spring. The average clutch size is around 19 eggs. The hatchlings emerge after an incubation period of about 50 days, each measuring about 35cm in length.