The Rock Monitor (Varanus albigularis) is quite similar to the Nile Monitor (Varanus niloticus).
However, the Nile Monitor has a pointed snout while the Rock Monitor has a large swollen snout.
Also, the Nile Monitor grows larger than the Rock Monitor and has a long flattened tail which assists in swimming.
The tail of the Rock Monitor is longer than the body and the body is dark brown/grey with dark blotches spread across the back.
The Nile Monitor is black with yellow blotches spread across the back.
Juveniles are more vividly coloured than adults.

The Rock Monitor is endemic to Central, East, and southern Africa.
It is the heaviest-bodied and second longest lizard (after the Nile Monitor) in Africa.
Adult males average about 6 to 8 kg and females weigh from 3.2 to 5 kg.
They can reach 2 meters in total length (including tail), with its tail and body being of equal size.
The Rock Monitor is found in a variety of dry habitats, including steppes, prairies, and savannahs, but is absent from desert interiors, rainforests, and thick scrub forests.
Three subspecies are currently recognized: V.a. albugaris, V.a. angolensis and V.a. microstictus.
This is varanus albigularis albigularis occurring in southern Africa and which is sometimes also called the White-throated Monitor.

Savuti Marsh, Chobe National Park, Botswana, 20 November 2001