Adults usually grow no more than 2m, but some have been recorded at 2.5m. There was however, one exception, one M.S. Variegata was recorded at 80cm at four years old.

The color pattern consists of a beige or brown ground color overlaid with blackish or gray blotches, cross-bands or stripes, or a combination of any of these. Regional color variations can include bright yellow, gold, rust and clear grays.

Found in New Guinea (Western New Guinea and Papua New Guinea) and Australia in northwestern Western Australia and in the northern portion of the Northern Territory. The type locality given is "North Australia: Port Essington" (Northern Territory, Australia).

The snake is not venomous and kills prey by constriction. Their diet is varied and includes many different birds and mammals. Populations that inhabit forested areas are mostly arboreal and often feed on brush-tailed possums, Trichosurus.

Oviparous, females deposit their eggs in secluded places such as hollow logs and tree boles where they protect and incubate them. Captive specimens have produced up to 18 eggs that hatch after a 40 day incubation period. The hatchlings are about 30cm in length.