I don't know about that. Sharks would have to be the best name.
Sharks and eels are Australian animals.
You find Sharks and Eels everywhere in the world. They are not "Australia" specific animals. Sharks actually migrate around joint. Eel are common in almost all continents.
Same applies to Broncos, Rabbits, Roosters, Bulldogs.. while Bears, Tigers, Panthers are predator animals from other continents and perhaps only the Sea-Eagles are a true Australian animal as we have native sea eagles all around the waterways and coastlines around Australia.
The unofficial nicknames for State of Origin, Canetoads & Cockroaches also falls into this.
On a side note the Bears got their name from a local grocery which sponsored North Sydney in the early 50's though ironically our first logo resembled a wombat more than a Bear, hence we were known unofficially as the wombats for a short time and finding a jersey with the "wombat" logo can be considered a treasured collectors prize for people who collect jerseys or emblems.