Black-headed monitor

At up to 60cm long, the freckled monitor (V. t. orientalis) is a smaller subspecies with a lighter, more distinct colouration, and a less spiny tail.

[2] Males can be identified after sexual maturity (usually around two years of age) by a large cluster of spiny scales either size of the animal's vent.

Female specimens lack these obvious protrusions and rarely possess more than a small number of spines only slightly larger than the surrounding scales.

[2] They are most active in the spring, and may travel a kilometre every day in search of food to accumulate enough fat reserves to last them through the six to seven cold winter months when they become inactive.

[2] V. tristis eats small mammals, frogs, other lizards such as agamids, geckos, skinks, and smaller monitor species.

Freckled monitor ( V. t. orientalis ), Queensland .
Black-headed monitor ( V. t. tristis ) in a sink with several dead lizards, Western Australia .
Skull