A book with a Centaur, Horse, and a Dragon on its cover.
Upon activation, a random Familiar (even locked familiars) will spawn and help Isaac for the current room. Can spawn one of the following:
- Brother Bobby
- Level 2 or 3 Cube Of Meat
- Halo Of Flies
- Distant Admiration
- Sister Maggy
- Little Chubby
- Little Gish
- Little Steve
- Guardian Angel
- Demon Baby
- Forever Alone
- Combined with items such as the 9 Volt, Habit, etc. can allow Isaac to have an army of familiars following him. Using this in a boss room can cause the boss to lose health very rapidly.
- The item and its graphics are both references to the D&D Monster Manual.
- The Monster Manuel is described as "evil" when it's unlocked.
- More than 3 orbitals may be active as a result using this item; this may have been done to avoid deleting old orbitals by accident, or could have been simply overlooked.