The anatomy and physiology of Japanese folk monsters.

For example, the monster above:

The Kuro-kamikiri (”black hair cutter”) is a large, black-haired creature that sneaks up on women in the street at night and surreptitiously cuts off their hair. Anatomical features include a brain wired for stealth and trickery, razor-sharp claws, a long, coiling tongue covered in tiny hair-grabbing spines, and a sac for storing sleeping powder used to knock out victims. The digestive system includes an organ that produces a hair-dissolving fluid, as well as an organ with finger-like projections that thump the sides of the intestines to aid digestion.

via Coudal