Quolls are carnivorous marsupials native to Australia and New Guinea. They are primarily nocturnal and spend most of the day in a den. Of the six species of quoll, four are found in Australia and two in New Guinea. Another two species are known from fossil remains in Pliocene and Pleistocene deposits in Queensland. Genetic evidence indicates that quolls evolved around 15 million years ago in the Miocene, and that the ancestors of the six species had all diverged by around four million years ago. The six species vary in weight and size, from 300 g (11 oz) to 7 kg (15 lb). They have brown or black fur and pink noses. They are largely solitary, but come together for a few social interactions such as mating which occurs during the winter season. A female gives birth to up to 30 pups, but the number that can be raised to adulthood is limited by the number of teats (6–7). They have a life span of 1–5 years.

Marsupials are a diverse group of mammals belonging to the infraclass Marsupialia. They are primarily found in Australasia, Wallacea, and the Americas. One of the defining features of marsupials is their unique reproductive strategy, where the young are born in a relatively undeveloped state and then nurtured within a pouch.