A Gashadokuro according to Japanese folklore is a giant skeleton many times taller than a human. It is though to be made of the bones of people who have starved to death. After midnight the ghost roams the streets making a ringing noise that sounds in the ears. If people do not run away when the Gashadokuro approaches it will bite off their heads with its giant teeth.

(Source - A Little Lesson in Japanese Ghost Lore: http://www.associatedcontent.com/article/691563/a_little_lesson_in_japanese_ghost_lore.html?cat=10)