Fey beings able to shift between humanoid and seal form using a magical sealskin

Selkies are fey beings able to shift between their native humanoid form, and that of a sleek seal. Their native humanoid form, resembles an elf, though their skin retains a faint shimmer, as if still touched by the sea, and their fingers and toes are webbed. Selkies unique ability comes from the magical seal skin they all carry, usually worn like a cloak, when a selkie wraps itself in this seal skin they (or anyone who steals their skin) transforms into its a seal in but a single round. Remaining in that form until they remove the skin. Selkie guard their sealskins with their very lives, for without it, they cannot return to their seal form. In their seal form, selkies may only attack with their bite, but in their humanoid form, they use weapons, favouring daggers, spears or shortbows.