Venomous land snakes unique to Australia, the brown snakes comprise a group of six species in the genus Pseudonaja; the genus is a rather loose classification with a wide range of variation in colour and pattern among the species. The eastern brown snake, Pseudonaja textilis, also known as the common brown snake, ranges in colour from light brown, through dark brown and orange to almost black. This snake grows to about 2.5 metres long and can be found from Cape York Peninsula down to the south-east of the continent.
The gwardar or western brown snake, P. nuchalis, inhabits a wide range of environments, from the tropics to the central deserts. It is a little less aggressive than the common brown snake and grows to about 1.5 metres. There are four other species of brown snake: the dugite, P. affinis, found in south-western Australia; the ringed brown snake, P. modesta, a smaller snake and the only member of the genus not considered dangerous; the speckled brown snake, P. guttata, and Ingram's brown snake, P. ingrami, both from the Northern Territory and Western Australia.