What are The Old Ones?

The Old Ones are almost semi-deities in the village of the Swampsea, they have the ability to mess with the lives of the villagers to near fatal degrees in order to simply be evil or to serve their own purposes, as the Boggy Mun does. They are sacrificed to by Briony, and the villagers live in constant fear of their power while also appreciating the balanced life they share.