While the obverse of the coin always depicts Queen Elizabeth II of Australia, the reverse side changes every year, always featuring a koala, a marsupial native to Australia.

The mint updates the monarch's portrait on obverse of the coin periodically.

[1] Silver koalas have higher collectible value than some other bullion coins due to the yearly design change and limited production.

Thicknesses are different based upon the yearly design of the reverse side.

Between 2008 and 2010, the only numismatic or proof coinage minted was the one-ounce with gilded koalas.