Flakes are a companion species to Manta-Pups, that have evolved alongside them, acting as sort of pets. They resemble a cartoonish caricature of regular fish, spouting four legs and a tail. They can range in appearance and size (ie. goldfish to a shark).
However unlike fish, they do not have gills or any functional gills for that matter, so they can't stay underwater for too long (Around 5-30 minutes).