Here are a few reasons why:
* Appearance: Quokkas have a round, plump body with short legs and a short, bushy tail, making them resemble a small, furry rat.
* Size: They are about the size of a large domestic cat, making them relatively small for a marsupial.
* Habitat: Quokkas are found on Rottnest Island off the coast of Western Australia, making them a popular tourist attraction.
However, there are other small, rat-like marsupials, including:
* Bandicoots: These are diverse, with some species having long snouts and others being more rat-like in appearance.
* Bilbies: These have long ears and a long snout, but their body shape is somewhat rat-like.
* Antechinus: Some species of antechinus are small and have a slender body with a long tail, resembling a rat.
If you can give me more information about the specific marsupial you're looking for, I can help you narrow it down!