The following is a list of demons, ghosts, yōkai, obake, yūrei and other legendary creatures, which are notable in Japanese folklore and mythology.
- Ibaraki-doji - Offspring of an oni.
- Ichiren-Bozu - Animated prayer beads
- Ikiryō - Essentially a living ghost, as it is a living person's soul outside of their body.
- Ikuchi - Sea-serpent that travels over boats in an arc while dripping oil.
- Inugami - A dog-spirit created, worshipped, and employed by a family via sorcery.
- Inugami Gyoubu - A type of tanuki.
- Isonade - A fish-like sea monster with a barb-covered tail.
- Issie - A lake monster.
- Itsumade - A fire-breathing bird-like monster.
- Ittan-momen - A possessed roll of cotton that attempts to smother people by wrapping itself around their faces.
- Iyaya - A woman whose face is reflected as an old man.
- Obake - Shapeshifting spirits
- Obariyon - Yokai which rides piggyback on a human victim and becomes unbearably heavy
- Oboroguruma - An oxen cart with a face in its carriage.
- Oiwa - The ghost of a woman with a distorted face who was murdered by her husband.
- Okiku - The plate-counting ghost of a servant girl.
- Ōkubi - The face of a huge woman which appears in the sky.
- Okuri-inu - Dog or wolf that follows travelers at night. Similar to the Black dog of English folklore
- Ōmukade - Giant, human-eating centipede that lives in the mountains
- Oni - The classic Japanese demon. It is an ogre-like creature which often has horns.
- Onibaba - The demon hag.
- Onibi - A spirit fire.
- Onihitokuchi - One-eyed oni that kill and eat humans.
- Onmoraki - Bird-demon created from the spirits of freshly dead corpses.
- Onryō - A vengeful ghost.
- Otoroshi - A hairy creature that perches on the gates to shrines and temples.
- Onmyoji - A human who has powers like a yokai's.
- Raijin - The God of Thunder.
- Raijū - A beast that falls to earth in a lightning bolt.
- Rokurokubi - A person, usually female, whose neck can stretch indefinitely.
- Ryuu - The Japanese dragon.
- Ubume - The spirit of a woman who died in childbirth.
- Uma-no-ashi - A horse's leg which dangles from a tree and kicks passersby.
- Umibōzu - A giant monster appearing on the surface of the sea.
- Umi-nyōbō - A female sea monster who steals fish.
- Ungaikyo - A possessed mirror.
- Ushi-oni - A name given to an assortment of ox-headed monsters.
- Uwan - A spirit named for the sound it shouts when surprising people.
- Waira - A large beast that lurks in the mountains, about which little is known.
- Wani - A water monster comparable to an alligator or crocodile. A related word has been applied to the Saltwater crocodile.
- Wanyūdō - A flaming wheel with a man's head in the center, that sucks out the soul of anyone who sees it.