Hailing from a world of heavy gravity, the Biri were assimilated into Bellum's military and unleashed on Hyrule. They are able to float effortlessly in Hyrule's atmosphere, delivering electrical shocks to their targets before flying to safety. The Biri are parasitic in nature and cannot survive without a host for long periods of time. Fortunately Hyrule's oceans are full of massive beasts to serve as breeding grounds.
Bird appear to be the juvenile stage of the maturer Bari. Larger in size than those employed by the Empire, Bari are shown to have vastly improved parasitic capabilities.