The Red-bellied Black Snake is widespread on the coast and ranges of eastern Australia. It is one of the more common species of large venomous snake still to be found in the Sydney region, and possibly still occurs in remnant bushland and the larger reserves on the northern foreshores of the harbour.

The Red-bellied Black Snake grows to 2 m in length, is black on top and as its common name suggests has a red or crimson coloured belly. It is found in a wide variety of habitats but tends to be most frequently seen in moister areas, particularly near water. Frogs form a large part of its diet and this may account in part for its apparent preference for wetter areas such as gullies in bushland remnants.