Kuchisake-Onna (The Slit Mouthed Woman) - Japanese folklore: She was once the very beautiful wife or concubine of a samurai. In a jealous rage, he mutilated her face. Her ghost returned, covering part of her face with a kimono sleeve, asking wanderers "Do you think I'm beautiful?" She would reveal her face with a 'yes' and ask "Do you think I'm Beautiful now?" Various bad things happen with just about any answer. Her modern form seems to wear a 'cold mask'; modern sightings have caused…
In Japanese folklore a Mu-onna, "nothing woman", is a type of yōkai, a supernatural monster. She is a vengeful spirit of a mother who lost her child to famine or war. She protects children in danger, but may also try to merge or absorb them. Since the Mu-onna is made from a mother's tender feelings, she may be willing to allow herself to be destroyed for the sake of the child.
Baku: The Legend of the Dream Eater: The baku, otherwise known as the ‘dream eater’, is a mythological being or spirit in Chinese and Japanese folklore which is said to devour nightmares. The baku cannot be summoned without caution, however, as ancient legends say that if the baku is not satisfied after consuming the nightmare, he may also devour one’s hopes and dreams.
Yanari -- Little demons that produce the creaking sounds heard in old houses. From The Kaibutsu Ehon ("Illustrated Book of Monsters"), an 1881 book featuring woodblock prints of yōkai, or creatures from Japanese folklore.
Umibōzu is a spirit in Japanese folklore. The Umibōzu is said to live in the ocean and capsize the ship of anyone who dares speak to it. This spirit’s name, which combines the character for “sea” with the character of “Buddhist monk,” is possibly related to the fact that the Umibōzu is said to have a large, round head, resembling the shaven heads of Buddhist monks. Alternatively, they are enormous Yōkai (spectres) that appear to shipwreck victims and fishermen.
Keukegen- Japanese folklore: a creature covered in black fur that lives in peoples houses. Its name means "rarely seen". It was a disease spirit, inflicting sickness into those who lived in its host house.