Bake-kujira

Bake-kujira, Bake-kujira and Hone-kujira are all names of a creature from Japanese mythology that looks like a ghostly skeleton of a whale.

He swims near fishing villages accompanied by strange, unprecedented and ugly fish and birds.

His appearance portends mass deaths, fires, famine, and so on, the youkai himself can curse some fisherman who sees him, and he, in turn, infects his entire village with a curse.