Reverse: the center of the coin depicts a tree branch of Eucalyptus, with Koala sitting under the leaves. The words "AUSTRALIAN KOALA" are at the top and the year "2015" at the bottom, "1 oz." and silver purity "999 SILVER". On the right hand side, the letter "P", which is the Australian label of The Perth Mint, has been cast in the middle.
Obverse: Queen Elisabeth II is featured in the obverse of the coin (in Australia, there is a constitutional monarchy under which her Majesty Queen Elizabeth II is also Queen of Australia). The words "ELIZABETH II" and the name of the state "AUSTRALIA" appear at the bottom of the queen, and the "1 DOLLAR" coin denomination at the bottom. The designer's initials IRB (Jan Rank - Broadley) are below the Queen's image.
About the coin: these Australian Koala coins were launched in 2007 and are rarer and extremely attractive to collectors. Each year the design of these coins differs.