The Southern Cassowary (Casuarius casuarius) is the third tallest and second heaviest living bird, smaller only than the ostrich and emu. They are very large flightless ratites, and a keystone species that distributes fruit seeds throughout the forest floor. They also take a range of other plant food including shoots, grass seeds, and fungi in addition to invertebrates and small vertebrates.

Cassowaries are usually shy birds of the deep forest, adept at disappearing long before a human knows they are there.