The Selkie

A.K.A: Silkies, sylkies, selchies.

Basic info

Scots for 'seal' or 'seal folk', seals that can shapeshift into humans and visa versa. They have a seal skin that they can put on and off, which causes them to transform. They get born with these skins, and if they get lost - or more commonly, stolen - they will be unable to return to their seal forme. In this case they will forever long for the sea, and live an unhappy life on land.

Apearance

They get born as seal pups, and shed their skin to move on land, much like the common mermaid. However, their human formes are closer to sirens, often atractive or seductive. In their seal forme they're usually depicted as grey and either regular or large in size, tho the type of seal they are depends on where the story originates.. Selkies can also have children with humans, both male selkies and female humans and visa versa, even tho the first option is more common in folktales. These children of male selkies will have webbed hands, and in some cases webbed toes. The children of female selkies and humans, however, have a lot of options. Here's some that I found: To be born with a seals face, greenish or white skin that is cracked (much like an old doll), a fishy odor (coming out of the cracks).

Personality

Selkies seem to have a human-like mind, as they are capable of having relationships (both platonic and romantic) with humans. Some selkies will be nice to humans, while other will be distant or even seek revenge for the seals they hunt for their skin and blubber (people used to make clothes, kayaks, etc. out of seal skin). They also have the same range of emotions as humans.

Time & Place

They seem to be most talked about in Norse mythology, especially Scotland. There's also stories from Shetland (Islands), Ireland, Faroe (Islands), Iceland and the Isle of Man. Stories of these creature date back to the 13th century, and there are movies that are relatively recent depicting them too (the latest one I could find was dated 2014).