Highly variable in colour and pattern, this arboreal lizard is found across northern Australia, from the east Queensland coast to the Kimberley in the west. They are also found in southern New Guinea. The medium-sized (60cm) monitor basks and forages on the trunks and branches of trees, and shelters in hollow limbs, tree holes and under the loose bark of these trees. It comes to the ground to feed on ground-dwelling lizards and insects.

Two subspecies are recognized - Varanus scalaris scalaris (from the NW) and Varanus scalaris similis (from Northern Territory and Queensland), though there may be further subspecies undescribed at this stage.