Nukekubi is a type of Rokurokubi. They are the same in all aspects except that the Nukekubi detaches their head completely from their body. It’s flying head can travel further than the Rokurokubi.

They look entirely like a normal human being during the day but they thirst for blood of humans or animals at night.

Just like the Rokurokubi, they will have no recollection of the violent bloodsucking nights they had after waking up.