also: ひゃっきやこう
nightly parade of demons; procession of monsters
Refers to the folkloric image of a horde of supernatural creatures parading through the night. Often used in historical or fantasy contexts.
Hyakki Yagyō is a legend in which Japanese yōkai form a procession at night.
pandemonium; a den of iniquity; a gathering of shady characters
Figurative extension: describes a chaotic situation or place teeming with unsavory people, as if a horde of demons were on the loose.
The downtown area late at night is like a veritable pandemonium.