Varanus kingorum Storr, 1980
This 50 cm lizard is common throughout the Kimberley Ranges, western Australia and nearby parts of the Northern Territory. Among its distinguishing features are its slender build and very long tail, which may be twice that of the body.
This lizard is usually found around rock outcrops where it feeds on various smaller animals. Specimens can be found under exfoliation's where they hide when disturbed. Although a small monitor, it has sharp teeth and will not hesitate to give a relatively sharp painful bite when caught.

The above was from the book Australian Reptiles and Frogs by Raymond Hoser and now available on a fantastic CD-Rom along with a vast amount of other information, papers and the like on reptiles, frogs and other wildlife.