Largest african lizard (total length may exceed 240 cm). Head elongate. Flattened tail longer than body. Head, body covered in small bead-like scales. Powerful limbs and strong claws. Blotched greyish brown and yellow to dirty olive-brown, light crossbands on the tail; juvenile brighter than adult. It is an excellent swimmer.
Common in major river valleys. Widespread in southern Africa except Western Cape and most of Namibia.