Susuwatari
Susuwatari are the "dust bunnies" or "soot sprites" featured in two animated children's movies:
My Neighbor Totoro and
Spirited Away. They are small, cute, black as soot and apparently fuzzy -- although they dissolve into poweder if crushed. They murmur to each other.
In Totoro, Mei tries to catch one, and later her family manages to rid the house of them. In Spirited Away, Sen befriends a bunch of them by helping them carry coal.