Hunter S said..
Goulds monitor, or sand monitor
Scientific name: Varanus gouldii
i'm pretty sure it's not a sand monitor. look at the tail. sand monitors have laterally compressed tails- the monitor in the photo has a round tail.
sand monitors always have a stripe running back from the eye, where gypsy's doesn't.
also, sand monitors are bigger than that little fella.
it's a varanus tristis, not gouldii