Yamabiko (folklore)
Yamabiko (山彦; also yamahiko) is a mountain god, spirit, and yōkai in Japanese folklore; the term "yamabiko" also refers to the echo that occurs in mountains, after which the yōkai is named. Literally translated, the term means "mountain boy". It is the yōkai responsible for the natural phenomenon in mountains or canyons. Living deep in the mountains, direct encounters with the yamabiko are rare. Often they are heard, but never seen. The small and elusive yokai wasn't officially classified until the Edo period in Japan. Instead the bizarre noises coming from the mountain were attributed to a natural phenomenon, like birds, and not given any spiritual significance. It is usually depicted with gray fur, peach-colored belly, floppy ears, large grin, and arms outstretched as though it is caught mid-shrug.