Oni

Oni (鬼（おに）, "Ogre") are hideous yōkai, usually wearing little to no clothing and possessing large claws, fangs, and horns. A notable exception to this rule is Urasue, an ogre sorceress. The inu daiyōkai Sesshōmaru often rode on the shoulders of large, red oni over a hundred feet tall into battle, before he obtained the demon sword Tōkijin from the fangs of the third Naraku's incarnations: Goshinki.

Notable oni yōkai

The Blacksmith Kaijinbō had fangs, horns and facial features resembling a typical oni, however it was never specified if he was one.
In the anime, the black miko Tsubaki unites with the Oni of the Forbidden Tower and becomes an oni hanyo.

Species
Yōkai	Badger yōkai • Bakeitachi • Bat yōkai • Bear yōkai • Bird yōkai (Demon birds) • Boar yōkai • Bull yōkai • Horse yōkai • Kappa • Kawauso • Lizard yōkai • Monkey yōkai • Oni • Oyster yōkai • Qilin yōkai • Rat yōkai (Fire-rat) • Root yōkai • Shinidamachū • Tree yōkai • Turtle yōkai (Meiōjū)
Canines	Dog yōkai • Kitsune • Tanuki • Wild dog yōkai • Wolf yōkai
Felines	Cat yōkai • Bakeneko • Nekomata • Leopard cat yōkai • Tiger yōkai • Wildcat yōkai
Insects	Flea yōkai • Mantis yōkai • Moth yōkai (Yōkai moth) • Ōmukade • Parasite • Saimyōshō • Spider yōkai (Kumogashira) • Steel wasps
Other	Human • Hanyō • Ghost • Specter • Dragon • Kami • Demigod • Shikigami • Kugutsu