Please note that the content of this book primarily consists of articles available from Wikipedia or other free sources online. Gazu Hyakki Yak? (The Illustrated Night Parade of A Hundred Demons) is the first book of Japanese artist Toriyama Sekien's famous Gazu Hyakki Yak? series, published 1776. These books are supernatural bestiaries, collections of ghosts, spirits, spooks and monsters, many of which Toriyama based on literature, folklore, other artwork. These works have had a profound influence on subsequent y'kai imagery in Japan. Y'kai (literally demon, spirit, or monster) are a class of preternatural creatures in Japanese folklore ranging from the evil oni (ogre) to the mischievous kitsune (fox) or snow woman Yuki-onna. Some possess part animal and part human features (e.g. Kappa and Tengu). Y'kai generally have a sort of spiritual or supernatural power. Y'kai that have the ability to shape-shift are called obake.