Kokochu

Kokochu (蠱壺虫) is an urn which contains a strange demon/entity which when released, enters human body and takes control of it. The demon holds a ringworm-like appearance and has no powers on its own. It works under the orders of its hive handler Tsubo Tsukai, who keeps and raises it in the urn. Naraku orders Tsubo Tsukai to manipulate Mushin, Miroku's guardian, using the Kokochu entity and kill Miroku. In the end, the demon is forced out of Mushin and the hive handler killed.