Kokuchi appear as beings that are black, red-eyed lizards with a blue tongue and fangs. Kokuchi Parasites retain the red eyes, black skin color, blue tongue, and fangs but, they have more centipide-like bodies.
Usually within the Shadow World, they are docile. If a tear appears in the human world and the Kokuchi enters the human world, the Kokuchi will go into a rampage and attack humans. If it is a Parasite Kokuchi, it might even possess a human. If the tear is small and barely any Kokuchi pass through, then the Kokuchi's counterparts; Hakua, will close the tear. If the tear is large and grand amounts of Kokuchi pass through it, the tear is requires a King or Direct King to seal.