Merfolk

Merfolk are a sentient semiaquatic species that split into two distinct cultures and species: The Aetillians and the Abyssal. Both have vast kingdoms in the seas, and are not part of any land dwelling country, as they claim autonomy over the oceans. Both species are peaceful towards each other and hold no ill will towards the land-folk. They existed before the Shatter, but it is not known if they appeared into the World at the same time as the other species, or if they originated in the Greenland.
After the Shatter, what is known is that they retreated into their ocean homes and fell into myth and legend. Their existence has only been re-discovered in the past two centuries. Before this, they were thought to be 'sea monsters' or the rantings of crazy sailors, as any record of their existence was lost during the Shatter.