an Ashiarai Yashiki is among the most unusual and legendary of Japan's many yokai and manifested as a giant disembodied foot, often covered in filth, that would often smash their way into homes and demand to be washed, failure to appease the spirit would result in massive destruction and even death to those involved.
Ashiarai Yashiki were completely alien in nature, even by the standards of yokai, so much so that some believed them to be shape-shifted forms of kitsune or tanuki - others believe they are symbols of past misdeeds of home-oweners, manifesting as spirits in order to torment them.