From Hakai, a story of a Seal Woman, aka Selkie.
Let’s start with the moral of this story: never piss off a seal woman. Ever.
Seal people—Selkies—are seal-human hybrids in the folklore of Irish, Scottish, Icelandic, and Faroese cultures. These mythological creatures live in the water as seals and, in some stories, come ashore once a year to human it up for a day. They flop out of the water and slip out of their fur, revealing their white, gleaming skin. And they dance. (Flamenco. Rumba. Disco. No one really knows what they dance, just that they’ve got feet for a day and they want to boogie.)
Read the rest of the story by Jude Isabella here.
And, if you've never seen The Secret of Roan Inish, treat yourself!