A large adult Eastern brown snake is a formidable creature. They may exceed two metres in length and, on hot days, can move at surprising speed. It has a slender body and is variable in colour ranging from uniform tan to grey or dark brown. The belly is cream, yellow or pale orange with darker orange spots. Hatchlings have a prominent dark patch on the top of the head and across the nape, and some hatchlings also have dark bands down the entire length of the body. These markings fade as they mature, however in some populations the bands are retained into adulthood. The Eastern brown snake is the species responsible for most deaths caused by snakebite in Australia. Although, with the advent of efficient first-aid treatment and antivenom, there are now usually only one or two deaths per year.
The Eastern brown snake inhabits most of eastern Australia from northern Queensland to South Australia. It inhabits a wide range of habitats but is particularly prevalent in open grasslands, pastures and woodland.
This species feeds mostly on small mammals, particularly rodents. It has rapidly developed a preference for introduced rats and mice and, for this reason, is often found around farm buildings. Such habits regularly bring the species in contact with humans and its bad temper and toxic venom may lead to potentially dangerous conflicts. Despite its reputation, it still performs a very useful function for farmers by controlling the numbers of introduced rodent pests.
Breeding activity for Eastern brown snakes begins in mid-late spring. During this time, males may be observed engaging in a ritualized combat dance with one snake trying to dominate and displace the other. The winner will then mate with the local females, who will produce clutches of up to 30 eggs in late spring or early summer. Depending on the incubation temperature, the eggs may take from 36 days to 95 days to hatch.