Gaboon Adders are rare and listed as Vulnerable. Have enormous fangs they grow to 40mm in length. Extremely dangerous to man but rarely encountered. A fat snake with triangular head very distinct from the rest of body. Beautiful colours in various shades of dark and light brown, buff, purple and pink. Always found on the ground, where it is confined to moist, thickly wooded forest regions. Strikes only as a last resort or is stepped on. Is Africa's largest adder.

The preferred habitat of the Berg Adder is montane grassland and rocky slopes from sea level in the Cape Province up to 3000m in the Kwa-Zulu-Natal Drakensberg. Colouring is grayish olive to dark brown or black, with silvery white dorsolateral line on either side. Above each line is a series of dark sub-triagular to semicircular pale-edged markings, and below these a series of similar but smaller markings forming a geometric pattern. Underside is off-white to dark grey, or occasionally slate grey to black. Like to bask in the sun. Hiss loudly when encountered. Strike readily. Bites may result in minor neurological symptoms but no fatalities are known.