Australian nocturnal marsupial (6)
![Ross](/clue/static/ross-mug.min.png)
I believe the answer is:
possum
(Other definitions for possum that I've seen before include "Tree-dwelling Australasian marsupial" , "Thick-furred marsupial" , "American marsupial (that plays dead?)" , "Small animal with a pouch" , "Dame Edna fan?" .)