The ventral scales often have dark margins. Adults reach 1 m to 1.5 m in length. Lowland Copperheads are usually found in open areas with low vegetation associated with streams, dams, lagoons or drainage ditches up to an altitude of 1000 m. Occasionally small specimens shelter in holes made by burrowing crayfish. Lowland Copperheads have also been recorded utilizing shearwater burrows on The Nut at Stanley and on islands.
Copperheads eat a variety of prey, typically feeding on lizards and frogs.
The species is well known for eating smaller snakes and is cannibalistic. Lowland Copperheads are also known to eat grasshoppers, and occasionally, carrion. This species is an active, alert hunter that is very shy with humans. With the increase in housing encroaching on the Copperheads preferred habitat, contact with people is more likely to occur. Copperheads are generally inoffensive and retiring, preferring to retreat when disturbed.