The 2023 1 oz Australian Silver Koala. The koala is perhaps Australia's most beloved and iconic animal. The cuddly koala 'bear' is not really a bear at all, but a marsupial. Protected by law, the koala inhabits trees and feeds solely on a diet of eucalyptus (gum) leaves. The reverse design depicts a charming image of an adult koala resting on the branch of a tree and incorporates The Perth Mint's 'P' mint mark.