In Ireland, Scotland, and England, there are mythical creatures called the Selkies. The Selkies or Seal Wives would have a seal-like skin in the water and would shed their seal-skin, whenever they surface on land. The word Selch in Scottish means seal.
The Selkies, like mermaids, had the ability to breathe underwater. For a Selkie, the sea was their one true home.
According to Welch legend, a Selkie was born on land, but chose to live in the sea. A female Selkie was revered for her stunning voice and alluring beauty.
A Selkie could only stay on land, for a short duration of time. They could only have a relationship with one human at a time and if they were to marry a human, they would have to keep their Selkie identity a secret. The reason, why they would have to keep their Selkie identity a secret, would be the fear that their magic pelts would be stolen from them and could no longer return to the sea.

Unlike some cultures, that believed that the mermaid was a sign of bad luck; the Welch, Irish, and Scottish, believed a Selkie was a sign of good luck. For fishermen, a Selkie was said to have brought them a bountiful catch.
A Scottish clan, named the Macdorum is believed to be descendants of the Selkies. The family has been said to be seals during the day and shape-shift into humans in the evening.