Legendary creatures of Japan; Kamikiri

(via)

Kamikiri is a large, black, bear-looking creature that attacks women from behind with a “mogaaaaa!” cry. It was later depicted with a human body and the head of a crow. Kami-kiri are known for sneaking up on people and cutting all their hair off, particularly when they are unknowingly engaged to marry a youkai, spirit or other supernatural creature that is disguised as a human. These hair-cutting attacks are intended to delay or prevent weddings between humans and otherworldly beings, which are typically doomed to failure. (via)