Cultural Notes
Ushi Oni
Demons
One of the most fearsome and formidable of yokai is the oceanic ushi-oni, an enormous and bloodthirsty beast usually drawn with a horned head like a bull or an oni, and a body like a gigantic crab or spider. It is a notoriously ruthless and violent monster said to lurk in the southern Sea of Japan, surging up onto the southwestern coast from Shimane prefecture down through Northern Kyuushuu to devour anyone unlucky enough to be caught on the beach.
Sometimes this ushi-oni is thought to be the husband of the yokai called nure-onna, as she sometimes emerges from the sea and tricks people into holding her "child" right before the great ox-demon attacks. The baby becomes stuck to the victim's arms and grows extremely heavy, making it harder for them to get away when the ushi-oni rushes hungrily out of the ocean. It is said a man was once saved from this sort of attack when his heirloom sword, animated out of concern for its master, left its place in his house, flew through the night like an arrow, and plunged itself into the monster's neck. The sword was lost, but the remaining scabbard was enshrined out of thanks.
Aside from the sea monster, the term ushi-oni has been used for bovine monsters all over Japan, such as the related freshwater gyuki of Shikoku, the bizarre ushi-oni that terrorized Negoro, and the cow-headed gozu who inhabits the Buddhist hell alongside its horse-headed companion. Man-eating ushi-oni also appeared in famous old literature such as the Pillow Book and the Taihei Chronicles.
Relevance to Inuyasha
Oshi oni make sporadic appearances throughout the series, and can usually be seen in crowd scenes where Inuyasha or Naraku slaughter numerous demons.