Common Brush-tailed Possum
Trichosurus vulpecula

The other common possum across much of the country (the other being the Common Ring-tailed Possum. The brush-tailed is larger (about the size of a cat) and has a wider range, occurring on both sides of the country. They make a strange series of guttaral grunting noises at night as well as hisses and coughs. These possums are commonly found to be nesting in buildings, which sometimes brings them into conflict with people. However, they are common and are not in any danger, except for the central Australian populaion which is endangered.
 

1: Mitchell Park, NSW, 05/06/2011.