ROUGH KNOB TAILED GECKO Nephrurus asper Gunther, 1876
Found throughout drier parts of Queensland, the Northern Territory and northwest Western Australia, including the Kimberleys, this distinctive gecko is usually found in rocky habitats.
Attaining 20 cm and of robust build, this is one of Australia's largest geckoes.
When walking, this lizard has its' body raised high off the ground, and keeps its tail off of the ground by having it also raised.
The Rough Knob Tailed Gecko will stalk and chase its prey, which consists of arthropods, spiders and smaller lizards.

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.