Pretty interesting if you have not heard about it.
Also called the Devil’s Bible.
"
According to legend the scribe was a monk who broke his monastic vows and was sentenced to be walled up alive. In order to forbear this harsh penalty he promised to create in one single night a book to glorify the monastery forever, including all human knowledge. Near midnight he became sure that he could not complete this task alone, so he made a special prayer, not adressed for god but for the fallen archangel “satan” asking him to help him finish the book in exchange for his soul, so the monk sold his soul to the devil. The devil completed the manuscript and the monk added the devil’s picture out of gratitude for his aid.[1][7]"
**It has been digitized also if you want to take closer look at it. **Link](The Codex Gigas – Devil's Bible | National Library of Sweden)
And here is a small Youtube video if you are like me and love documentaries.