From the introduction:
The inspiration for this project comes from “One Hundred Monsters Ancient and Modern” - specifically from the book “Konjaku Hyakki Shūi”, by the 18th century ukiyo-e artist Toriyama Sekien.
The source book is available online at https://www.metmuseum.org/art/collection/search/78693 and is released under Creative Commons CC0 1.0 Universal (CC0 1.0) Public Domain Dedication - https://creativecommons.org/publicdomain/zero/1.0/
This derived work is released under Creative Commons Attribution-NonCommercial 4.0 International (CC BY-NC 4.0) - https://creativecommons.org/licenses/by-nc/4.0/
"Konjaku Hyakki Shūi (今昔百鬼拾遺, ‘Supplement to The Hundred Demons from the Present and the Past’) is the third book of Japanese artist Toriyama Sekien's Gazu Hyakki Yagyō tetralogy, published c. 1781. These books are supernatural bestiaries, collections of ghosts, spirits, spooks and monsters, many of which Toriyama based on literature, folklore, and other artwork. These works have had a profound influence on subsequent yōkai imagery in Japan. Konjaku Hyakki Shūi is preceded in the series by Gazu Hyakki Yagyō and Konjaku Gazu Zoku Hyakki, and succeeded by Gazu Hyakki Tsurezure Bukuro."
- - https://en.wikipedia.org/wiki/Konjaku_Hyakki_Sh%C5%ABi
Monster Recovery Effort is the result of a collaborative project completed on RPGGeek. Based on the images from the book, users of the RPGGeek forum created the descriptions collected here. Despite the influence of the source material in Japanese culture, Toriyama's prints are little known among RPG players from North America and Europe. His creatures haven't had the chance to bend, spindle, or mutilate player characters for too many years. They want to come out and play. They want to eat fighters, skewer magic-users, and frighten children. Some want to spice up your settings and backdrops, hiding behind the whispered tales they leave in their wake. Others want to roar, skulk, leap, and strut their stuff. Monsters change and grow and surprise, so we allowed them to enter our imaginations and become something new.
We’re re-using the artwork as a source of inspiration to create new monster and creature concepts for roleplaying. However, we do not intend them for any particular game or style of play. You will not find numerical stat blocks, and not every entry in this bestiary should be treated as an opponent for an adventuring party looking for experience points. While the original Japanese text is still in the images, Monster Recovery Effort provides new descriptions for these creatures - much like a contrafactum in which new text replaces lyrics for an existing piece of music. We hope you will enjoy both Toriyama's work as well as ours.