Which of these is a remarkable mammal that lives only in Australia?

The platypus is a remarkable mammal found only in Australia. The platypus is a duck-billed, beaver-tailed, otter-footed, egg-laying aquatic creature native to Australia. If its appearance alone somehow fails to impress, the male of the species is also one of the world’s few venomous mammals! The female platypus lays her eggs in an underground burrow that she digs near the water’s edge. Baby platypuses hatch after 10 days and nurse for up to four months before they swim off and forage on their own. There is only one other egg-laying mammal in the world: The echidna, a distant cousin of the anteater.

Source: Ocean Service