A three-headed giant raven that is the favored prey of red and green dragons, rocs, and wyverns. Because they're tasty or something.
...I'm so confused.
Horrendous CR 11 Magical Beasts, corpsepinners are another pf the demented residents of the Astral Plane, hunting astral sharks and planar travelers. While being a giant astral spider with venom-laden fangs and a deathly pallor wasn't creepy enough, corpsespinners are also intelligent and capable of necromancy. Yes, necromancy. They create their own form of undead known as the corpsespun, which we'll meet when we reach the templates appendix. This means that a fight with a corpsespinner can be livened up by web-mummified croneys of many different sorts. This means you can induce both arachnophobia and necrophobia in the same encounter, hooray!
Yet another monster with ties to the first ToH, the cranky crag men are evil CR 5 Aberrations (no clue why they aren't elementals, as they are vaguely humanoid chunks of rock) that have long been at war with the vilstrak for some reason. While most captives of the crag men are captured to be eaten, the tunnel thugs are killed on sight or enslaved. In combat, crag men are brute force fighters with their spiky hands, but also have the stealthy ability to camouflage themselves by reverting to their natural form: that of a stalagmite. And speaking of the stalags, the big power the crag men have is that they have a 50-50 chance of being able to produce a "piercer hellstorm", raining down 2d10 piercers. Ouch.