Does not look like a Ring-tail to me, that has almost no pattern, and looks a fair deal grown using that log as a reference. It's certainly a Ctenophorus though.
More details: Where's it from, why's it in a cage, why don't you know what it is. Etc.
Do you have a locality or where the parents originated from?
It is a baby Crested Dragon (Ctenophorus cristatus). It has the nuchal crest and the dorsolateral line of enlarged spinose scales diagnostic for this species. The last two-thirds of the tail will be banded. In the Ring-tailed dragons (C. caudicinctus) the banding on the the tail starts at the base of the tail and while they have the well developed nuchal crest, they lack the dorsolateral crest of spines.