Selkie

The seal folk change their shape between that of a seal and that of a human through shedding their skin, which they then keep as a coat allowing them to return to human form. 

Selkie society is based in small isolated fishing villages throughout the world, and they are one of the few faery races unaffected by the dreaming, perhaps due to their ability to sense mana pathways and make migrations along them under the oceans to the few working underwater fortresses.

They take pains to keep their communities hidden from the modern world, using fairy glamour to cause their villages to appear as small rocky islands where seal colonies live.