Rat shaped. If it is rat-sized, not mouse-sized, then it will be either the native Bush Rat, Rattus fuscipes, or more likely the introduced Black/Roof Rat, Rattus rattus. The only difference between these species, that could be picked up in an image like this, is the ratio of tail length to head-body length. Rr has a tail longer than HB. But sometimes the thin end of a tail is not picked up in low res trail cam image