Sirens
Merfolk
Sirens are a species of fae-origin, part human and part aquatic animal. Despite the legends, they strictly consume vegetation. Regarding the humans and fish they share harbour with, they often prefer to stir trouble and play tricks. They are known to teach lost sailors of the stars, often spreading rumours and whispers they hear from bay to bay. While most appear for the most part recognisably still human, those living in the yet-deeper abyss do not share this trait as often: sirens of that kind are called Deep Sirens.
Land-Faring
Sirens can, in fact, tread land. Sirens are naturally more arcanely equipped, the manner with which they echo-locate making them more in tune with the Anthem with greater understanding than land-folk. Due to their added proficiency, those with an understanding of Epoch-Arcana, the magic of alteration, can sprout, of all things, legs. Their tail, though usually smaller, stays while in this form. They do not fare well in arid environments though, and are often hard of hearing due to the difference with land-farer speech versus their native method of echo-location.