The Namahage is one of the variations of the Namahage category of demon, and it is first encountered at Kamui, outside of Oki' hut. It has a green mask, straw raincoat and a sign (the one used to mark locations, not the arrow signs for giving directions). It also has guards on its forearms and shins, and a simple pair of sandals.
The Namahage is depicted as the embodiment of loneliness in snowy lands. It seeks living beings and attack them. When one encounters a Namahage, is recommended that that person plays dead, as this demon regards the indolent as allies and cease their guards.
"Namahage are the embodiment of the loneliness inherent in snowy lands.
Raising a terrifying voice, they seek out and attack living things.
If you cross paths with one, you should play dead.
They regard the lazy as friends and are lulled into a false sense of security."