Adult Copperhead snakes have a coppery coloured head and neck. Copperhead snakes are medium sized snakes, with adults normally reaching 80 centimetres – 1.2 metres (2 – 4 feet), with thick, heavy bodies. Their body is more slender, however, compared to most other pit vipers. There are five clearly defined subspecies. All subspecies have distinctive light and dark brown or greenish banding.

Copperhead snakes can be found in most all habitats, although they often prefer to be near streams and other waterways. Copperhead snakes prefer habitats with lots of vines, vegetation and debris. Their colouration and patterning is very effective for camouflage in dead leaves on the forest floor. Copperhead snakes may be found on hilltops or lowlands. It is not unusual for Copperhead snakes to be found in forested or undeveloped areas within and near suburban developments.

The Copperhead snake is one of the most successful of the larger snake species. Copperhead snakes rely upon camouflage and cover for safety when danger is perceived. It is usually not difficult to find a Copperhead snake crossing a road on a warm summer night. Because Copperhead snakes have a habit of freezing at the approach of danger, many are killed by vehicle traffic.

The Copperhead snake is venomous, however, their bite is almost never deadly to humans and they are generally non-aggressive. Copperhead snakes have an efficient venom delivery system, with long fangs mounted at the front of the jaw which swivel back to allow the snake to close its mouth.