An apkallu is an aquatic bird that inhabits the coastline of the island of Vylbrand. While unable to affect flight, the apkallu's wings serve as powerful flippers that propel it through the water with amazing speed and grace. In order to bring the fish it swallows back to its hungry chicks, an apkallu is capable of voluntarily suppressing the production of its own digestive acids. When threatened, however, the normally placid creature can reverse this effect, allowing it to vomit forth its belly's caustic contents at a moment's notice.
— Encyclopædia Eorzea vol 1
All creatures belonging to the genus Apkallu.