Chimimōryō (Chinese: 魑魅魍魎; pinyin: Chīmèi wǎngliǎng) is a Japanese word of Chinese origin for mountain monsters and river monsters.
It refers to different kinds of obake and things transformed into yōkai. "Chimi" (魑魅) refers to mountain monsters and "mōryō" (魍魎) to river monsters so the word "chimimōryō" is often used to refer to all mountain and river monsters.
In addition, the word "minori" has also been used for this purpose. For this to be used to refer to a maturing oni (minoru) has been used in various regions since ancient times.
Chimi are said to be monsters from which strange atmospheric miasma emanates in the mountains and forests. Appearing with the face of a human being and the body of a beast, they perplex humans.
In the Heian-era Wamyō ruijushō dictionary, they are considered a type of oni under the Japanese name "sudama," and in the Edo-era Wakan Sansai Zue encyclopedia, they are seen as mountain deities (yama-no-kami).
The mōryō are seen as spirits of mountains and rivers, trees and rocks. They emanate life energy from mountains, water, trees, rocks, and all sorts of things in nature and deceive humans.
In addition, they are also said to eat the dead, have the appearance of a child, stand on two feet, have dark red skin, red eyes, long ears, beautiful hair, and a human-like voice.
With this kind of appearance, they are supposed to be oni. In the Wakan Sansai Zue, they are considered to be water deities (suijin) and in the ancient Chinese book Zuo Zhuan, they are considered to be gods of swamps and marshes.
There are many theories regarding the etymology of the Chinese word, but according to the Memoirs of the Great Historian (during the Five Emperors period), a 魑 is a mountain deity who took the form of a tiger and a 魅 is a swamp and marsh deity taking a beast-headed form.
It is assumed because of this that the word was seen as a way to expand the concept it covers to include beasts of different attributes.