From the Super Mario Wiki
Retrieved from "https://www.mariowiki.com/index.php?title=Birdoroo&oldid=2234034"
Birdoroos are a species of Birdos that inhabit Down Under Land. They resemble kangaroos due to the fact that they get around by hopping, and because the adults (most likely just the females) have pouches for carrying their babies. Although Birdoroos will keep to themselves if not provoked, they are also territorial, and will assault anyone who invades their swamp with Birdoroo Eggs. Adult Birdoroos also wear Akubra-style hats.
Birdoroos only ever appeared in The Super Mario Bros. Super Show! episode "Crocodile Mario", where some could first be seen hopping around Down Under Land, minding their own business. However, when Mario and Luigi passed by their territory on a raft, several Birdoroos launched an onslaught of eggs in their direction, which they barely managed to dodge.