Hyakki Yakou (百鬼夜行?) is an RPG published by Use for the Famicom in 1989 that is based on Hyakki Yakou, or "Night Parade of the 100 Demons", a Japanese festival akin to Halloween. Hyakki Yagyō is an idiom in Japanese folklore. Sometimes an orderly procession, other times a riot, it refers to an uncontrolled horde of countless numbers of supernatural creatures known as oni and yōkai. As a terrifying eruption of the supernatural world into our own, it is similar (though not precisely equivalent) to the concept of pandemonium in English.

The game is otherwise a fairly traditional 8-bit RPG, though it does feature uncommon aspects such as being able to see enemies while walking around (as opposed to the then-usual random encounters) and a regularly-proportioned adult protagonist. There is also no overworld map - both the towns and monster-infested wilderness are directly connected. It was never released outside of Japan.