A black hound has green fur; his neck is the only area with white hair. It has a fairly short tail and teeth that are very sharp and piercing. When it does not feel threatened at all, it shrinks into a small dog.
Black Hounds are wild predators who are insanely vicious and will not stop hunting their target until he are either dead or they are done with him. But occasionally, they can be domesticated as King tamed Oslo and befriended him.
Black Hounds are very powerful and fast, seeing as how one of them was able to easily defeat Andre and his partner, who were both apprentice Holy Knights. They also have the ability to change their sizes depending on how threatened they feel; black hounds grow huge if threatened greatly and shrink to a very small size, equivalent to a small dog, if not threatened at all. Black Hounds also have the unique ability which allows it to send anything it swallows to a completely different location.