Nature: Book
Language: whatever language helps it blend in
Author: Will Worker
First Encountered: 3.4 "Sinister Symbolism"
Description: Has a ribbon tied around it. The team retrieving it (4.4 "Reap Between the Lines") decided that it was best to mark it in case it actually decided to camouflage itself. A wise precaution, as the Paranormal Division workers they handed it to learned.
Information: Attempts to blend in with nearby books. The original is only visible and readable when on its own. It then describes a multitude of magical hiding and concealing techniques. Some of which have been confirmed to be traps; they are suicide recipes instead. It is still unknown whether any of the methods described actually work.
When blending in with other books, it does so imperfectly. This makes it dangerous in that state as well if mixed with powerful book. Pretending to be spell book but having a work syllable in most lines would lead to disastrous consequences, after all.