The mermaid is, most likely at least, an enemy in The Witcher 3: Wild Hunt.

Half barely-clothed, scaly female, half fish, these lithe creatures swim through the seas smooth as silk and are infamous for seducing sailors, pirates, fishermen and travellers. With their divine, otherworldly beauty, enchanting voices and graceful bodies, mermaids can easily enchant the hearts of any sailor.

Though beautiful, mermaids are dark creatures. In many stories, creatures such as these would lure men into the water and then devour them.