The Australian marsupial often mistaken for a monkey is the cuscus. Cuscuses are tree-dwelling members of the possum family, and their large eyes, rounded faces, grasping feet, and slow movements can give them a distinctly primate-like appearance.
The common spotted cuscus is especially associated with this confusion. Its scientific name is Spilocuscus maculatus, and it has a thick coat that can range from pale cream to orange, gray, or brown. It lives in rainforests and other wooded habitats in New Guinea and the far northeastern tip of Australia.
Despite its appearance, a cuscus is not a monkey and is not closely related to primates. It is a marsupial, meaning females give birth to very underdeveloped young that continue developing while attached to a teat inside a pouch. Cuscuses are adapted for life in trees, using their prehensile tails and strong claws to climb.
Their nocturnal habits also contribute to their unusual look: large eyes help them see in low light. The name cuscus refers to several related species, so the broader answer is correct even when a particular spotted species is intended.