They have a small head, pointed nose, catlike whiskers and large oval ears.
The possums fur is thick and woolly and the colour, though usually brown, can be variants of grey as well.
Their tail is long, black and bushy and they have sharp claws which they use for climbing trees and grooming.
Possums are marsupials - meaning that the females carry their young in a pouch.
They usually give birth in the winter after just 17 days gestation and the newborn possum finds its way to the mother's pouch and attaches itself to a teat.
The young possum usually spends up to 5 months in the pouch before moving to cling to its mother's back for about two more months.
Possums generally only have one young at a time and are fully grown at ten months although not reaching sexual maturity until about a year.
Other than when breeding, Possums are solitary creatures and tend to stay within their own 'range' which they claim by covering tree branches with a scent released from glands on their chest.
They nest in forests and woodlands either in the trees or under vegetation, in hay stacks and even in the roofs of buildings!
Possums are nocturnal and so are rarely seen during the day.
The diet of a possum is varied - they eat almost anything and can cause considerable damage to flora and fauna as not only do they they eat leaves and berries from trees but also strip their bark. Their diet can also birds eggs and young birds, agricultural crops and even insects.
Some countries have attributed the spread of Tb in Cattle and Deer to Possums.
Possums are native to Australia, New Guinea and Sulawesi but were then introduced to New Zealand in the early nineteenth century.