Mermaids are an alluring humanoid species that live in the Sea of Mermaids. They all have similar appearances - young females with cyan hair and eyes. At least one of the mermaids is able to transform into a Grinwhale.
Mermaids use their allure and tales of despair to lure sailors and adventurers to their island to be consumed by the Grinwhale to satisfy their hunger. Mermaids appear only very rarely in the game, but they are really very ferocious. Humans can easily be lured by them, and thanks to Feena, who is an Icarian, Justin was saved from the Grinwhale.