Two common species of varanids within Western Australia are Varanus gouldii, and Varanus panoptes. These two species are often confused. While having similar appearances, V. panoptes tend to grow larger and stockier than V. gouldii, and vary slightly in patterning. V. gouldii appear to have a more uniformly patterned body than V. panoptes, which typically have several well defined yellow spots. The following are some photos of each species.
Varanus gouldii (Goulds monitor)
Varanus panoptes (Yellow spotted monitor)