Rokurokubi are yokai found in Japanese folklore.
Female ghosts with the ability to stretch their necks to great lengths at night and habbit to scare others.
According to some tales, rokurokubi were once normal human beings but were transformed by karma for breaking various precepts of Buddhism.
Brother: I like them, if I could, I would marry a rokurokubi!
Sister: For their deep throats 'coz I don't see another reason?...