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The Grimoire Minosaur is an inanimate object Minosaur created by Kureon of the Druidon Tribe from the negative emotion of Shotaro, based on his stress from being captured by the Druidons and unable to paint with his younger brother Kyohei and an antagonist in episode 20 of Kishiryu Sentai Ryusoulger.
The Grimoire Minosaur was created by Kureon from a painter named Shotaro, who was stressed about not being able to paint with his brother Kyohei.
Wizeru thus used the sketchbook to create cages to trap all of the Ryusoulgers, imprisoning all of them except for Towa, who managed to evade capture.
The sketchbook eventually grew larger from Shotaro's continued stress, allowing Wizeru to use it to create a giant version of himself. However, Towa manages to leap onto the Grimoire Minosaur page to draw seven keys to free everyone captured by it and allowing the Ryusoulgers to form Kishiryu'Oh and finish off the giant Wizeru while the book is sliced by KishiRyuNeptune.