The Mulga snake has the largest recorded venom output of any snake. It is found throughout Australia, except in Victoria, Tasmania and the most southern parts of Western Australia. The name "King Brown" snake may lead to confusion and to the incorrect use of brown snake antivenom, and is therefore best avoided. It feeds on rats, mice birds, lizards and other snakes. It is frequently active at night, especially in hot weather.
It is heavily built, being in fact the heaviest Australian venomous snake. The body is uniform in colour, usually light brown, but there is some variation between individuals. The average length is around 1.5m, and the record length greater than 3m. Mulga snakes are oviparous (egg-laying). They may become aggressive and strike repeatedly if threatened.