Platypus.
These guys are about 350-450mm long (14-16 inches).
Platypus are intriguing animals as they are one of only two mammals that lay eggs but suckle their young with milk, the other being the Echidna (spiny anteater) and both are only found in Australia.
This group of animals are callled Monotremes.
The Platypus are endemic to eastern Australia and Tasmania only.