The Forest Father is a god revered by the Ewok race that are from the Forest Moon of Endor. The Ewoks thought that this spirit kept watch over them and heard their requests. Young Ewoks were instructed about the Forest Father, as well as other things about the forests they lived in, once they were able to walk.
Joe Johnston conceived of the Forest Father for his children's book called The Adventures of Teebo: A Tale of Magic and Suspense, which came out in 1984.