It's described as a sort of bird / insect mash-up. With a not-so scary illustration. If this thing is a Horror, in a book of monsters, it should be a lot scarier. Hellraiser scary.
The Hook Horror is a large spider-like creature covered in feathery black hair. It uses its long hook tipped legs to hang from trees, rocks and other elevated surfaces to wait for victims. Beneath its black bristles the beast is covered in barbed and hooked quills making it perilous to approach. Worse still, the Horror can shoot these hooks short distances to snare victims and drag them back towards its long reaching legs, and up toward a razor filled mouth. Hook Horrors are know to lower their hooks down from the shadows to snare unsuspecting victims below.