Quokka

The quokka  the only member of the genus Setonix, is a small macropod about the size of a domestic cat. Like other marsupials in the macropod family (such as kangaroos and wallabies), the quokka is herbivorousand mainly nocturnal. Quokkas can be found on some smaller islands off the coast of Western Australia, in particular onRottnest Island just off Perth and Bald Island near Albany. A small mainland colony exists in the protected area of Two Peoples Bay Nature Reserve, where they co-exist with Gilbert's potoroo.

The quokka weighs 2.5 to 5 kilograms (5.5 to 11.0 lb) and is 40 to 54 centimetres (16 to 21 in) long with a 25 to 30 centimetres (9.8 to 11.8 in) long tail, which is fairly short for a macropod. It has a stocky build, rounded ears, and a short, broad head. Although looking rather like a very small kangaroo, it can climb small trees and shrubs. Its coarse fur is a grizzled brown colour, fading to buff underneath.The quokka has little fear of humans and it is common for it to approach them closely, particularly on Rottnest Island. It is, however, illegal for members of the public to handle the animals in any way on Rottnest Island. 
An infringement notice carrying a A$300 fine can be issued by the Rottnest Island Authority for such behaviour. In addition, prosecution of the offense can result in a fine of up to $2,000. It has however become popular to take selfies, with the animal, where it seemly smiles, causing many to call it 'the happiest animal in the world'. The quokka was one of the first Australian mammals seen by Europeans.

The Dutch mariner Samuel Volckertzoon wrote of sighting "a wild cat" on Rottnest Island in 1658. In 1696, Willem de Vlamingh mistook them for giant rats and named the island "Rotte nest", which comes from the Dutch word rattennest meaning "rat nest".The word quokka is derived from a Nyungar word, which was probably gwaga. In the wild, its roaming is restricted to a very small range in the South-West of Western Australia, with a number of small scattered populations. There is one large population on Rottnest Island and a smaller population on Bald Island near Albany. The islands are free of foxes and cats. On Rottnest, quokkas are common and occupy a variety of habitats ranging from semi-arid scrub to cultivated gardens. Like most macropods, quokkas eat many types of vegetation, including grasses and leaves. A study found that flowering plants of the genus Guichenotia are one of the quokka's favourite foods.