Ashi-magari

Ashi-magari (足まがり, leg turner) is a ghostly phenomenon from the folklore of Kagawa Prefecture on Shikoku, Japan. It is a soft thing, like a kitten or a wad of cotton, which is felt wrapping itself around a person's leg at night, impeding the ability to walk. While it is not generally visible, it is often believed to be the trick of a tanuki.

References

Kaii-Yōkai Denshō Database: Ashi-magari