Jinmensō 人面瘡

The human-face sore: a lesion that has taken a shape it should not have. The name is a description of an appearance and claims no agent — no demon, no possession, no curse. That is where the subject starts and where most English accounts of it do not, because it reaches the anglophone internet as a monster entry, a talking sore that demands to be fed. The older Japanese handling is medical. It turns up in Edo writing not as a subject but as an agreed premise, cited in passing alongside another strange complaint to establish that odd diseases exist.