From Lost Fables Wiki
Friendly denizens of the sea, mostly, Merfolk are a group of Ae Il’ha, who instead dwell entirely in the sea, having long since gone through a steady process of transforming into what they are today. From the waist up, minus their webbed hands, they appear to be as any Ae Il’ ha does, fair skin, pointed ears and all, but below the waist they have the scaled body of some huge fish, allowing them to swim quickly and powerfully through the water. Though their civilization, without the benefits of fire, looks to many to be a rather simple one, the Merfolk enjoys this simple life, farming, fishing, and living in relative peace and security under the waves.
Strong Oceanic Truths, extremely fast in water.
Basically harmless on land.