Tsurube-otoshi is a creature from Japanese

Japan

Japan is an island nation in East Asia. Located in the Pacific Ocean, it lies to the east of the Sea of Japan, China, North Korea, South Korea and Russia, stretching from the Sea of Okhotsk in the north to the East China Sea and Taiwan in the south...

 folklore

Folklore

Folklore consists of legends, music, oral history, proverbs, jokes, popular beliefs, fairy tales and customs that are the traditions of a culture, subculture, or group. It is also the set of practices through which those expressive genres are shared. The study of folklore is sometimes called...

. It lurks in the tops of trees and drops down on unsuspecting humans, and has various descriptions - sometimes it is some sort of oni or tengu

Tengu

are a class of supernatural creatures found in Japanese folklore, art, theater, and literature. They are one of the best known yōkai and are sometimes worshipped as Shinto kami...

, sometimes it is a disembodied head, and sometimes it is a fireball. Its name is an expression for "falling quickly" which literally means "a well-bucket dropping", and sometimes the tsurube-otoshi instead drops a well-bucket to scoop up its prey.