How to Identify the Mulga Snake (Identification Guide)

Key identifying features

The Mulga Snake (Pseudechis australis), also widely known as the King Brown Snake, is one of the largest and heaviest-bodied venomous snakes in Australia. Its sheer bulk, broad head, and coppery-olive coloration are the main features that set it apart from the slimmer "true brown snakes" it is sometimes confused with despite the similar common name.

Coloration & pattern

Coloration ranges from coppery-brown to olive, tan, or dark reddish-brown above, often with each scale edged slightly darker, giving a faint reticulated or cross-hatched appearance across the body. The color can look almost uniform in dim light but shows subtle scale-edge patterning in good light. The belly is cream, pale yellow, or pinkish, sometimes with darker mottling toward the tail.

Head, eyes & scales

The head is broad, deep, and somewhat distinct from the neck, larger and more robust in proportion than the heads of true brown snakes. Eyes are of moderate size with dark irises. Scales are smooth but the overall build gives the snake a heavier, more muscular look than more slender elapids in the same regions.

Size & body shape

This is a large, thick-bodied snake, with adults regularly reaching 1.5 to 2 meters and occasionally approaching 3 meters, with a correspondingly heavy girth. The body is cylindrical and powerful rather than tapering and slim, giving an overall impression of bulk and strength distinct from most other Australian elapids.

Range & habitat where you'll see it

The Mulga Snake has one of the widest distributions of any Australian snake, occurring across arid and semi-arid mulga woodland, grassland, and scrub throughout much of the continent's interior, as well as some tropical and coastal areas. It shelters in burrows, hollow logs, and under debris, and is active both by day and night depending on temperature.

How to tell it apart from look-alikes

Despite the shared common name, the Mulga Snake is not closely related to the true brown snakes (Pseudonaja species) and can generally be told apart by its notably heavier build, broader head, and coppery-olive scale-edged pattern versus the slimmer, often uniformly colored true browns. Compared to other Pseudechis (black snakes), the Mulga Snake's paler, coppery tone contrasts with the typically glossy black or dark grey coloring of species like the Red-Bellied Black Snake. Overall size and bulk are often the quickest clue: few other Australian elapids reach the same combination of length and girth.