Yamabiko: A yamabiko (山彦, 幽谷響) is a sprite/youkai/god known in the Japanese folklore. In modern Japanese, yamabiko (やまびこ, 山彦 ["幽谷響" can't be used here]) is a word that refers to the phenomenon of the "reflection of sounds in mountains or valleys". In the old days of Japan, people thought echoes occurred because a yamabiko living in the mountains replied back or manipulated the sound.
