The Hill of Ull is one of Arden's oddities. From generation to generation it seems to move where it rests inside the great wood. What remains constant is that it is a large hill, covered in moss and loose dirt, topped by a massive pine tree.
Some of the Rangers and Denizens know the truth of the Hill of Ull, however. It is not a hill at all, but a giant bound to the will of the Warden. Ull is the name of the creature, and he sleeps until the Warden's horn sounds, calling him from his slumber and to purpose. He is bound to do one duty before the enchantment is broken and Ull is unleashed upon the unsuspecting.
Ull can be put to sleep with a net woven of flowers placed over his head. The earth will cover him as a blanket, the deep song lull him to sleep, his club sprouting as a tree, anew. Of course, it's easier said than done and easiest of all done when he slumbers after a meal of mutton and virgins.