Detachable neck or head wanders at night

Rokurokubi

Some tellings distinguish a separate but closely related type, the nukekubi, whose head detaches from the neck entirely and flies off on its own to hunt at night, rejoining the body before dawn; accounts vary on whether these are two names for one being or genuinely distinct yokai, and Edo-period storytellers and artists, including Toriyama Sekien in his yokai compendia, treated both forms as part of the same broader category.