Codex of Ultimate Boredom

The codex is the one of the "Fabulous Items of Tibia". You can see this book under the Plains of Havoc, near the Pits of Inferno entrance . Just go down the hole leading to the Well of Life and look on your left side. Unfortunately, there is no possible way to visit the cave with the book and the rest of the "fabulous" things, so the contents of the book (if any) are unknown.