This item belongs to the Bookworm set. Collecting three items from this set will transform Isaac into Bookworm.
Orbital bones deal contact damage equal to Isaac's damage at the time it was spawned and repel enemies that touch them.
They block 3 shots or deal 2 ticks of contact damage before being destroyed.
Bonies deal 8.3 contact damage and 5 damage with thrown bones.
Bonies deal 8.7 contact damage and 6 damage with thrown bones.
Black Bonies will explode on death, dealing 40 damage to enemies it hits. The explosion will not hurt Isaac, but will knock him back.
Internally, the Book tracks each position an enemy was killed at in the current room, and uses those locations as spawn points for bone orbitals and Bonies; using the book gives a **high probability** for each location to give one of them.
If one of these locations doesn't give a bone orbital or bony, it can still give one if the book is used in the same room without leaving. However, once a location gives something, it cannot do so again.
Using the book in a room that had no enemies or was re-entered does nothing and expends the charge.
Orbital bones occupy the same area around Isaac as Blue Flies, meaning Isaac can have an incredibly dense ring of bone orbitals around him that nullifies most attacks.
Friendly monsters killed in the current room can also be used by Book of the Dead.
Destroying black poop will damage the friendly Bonies acquired from this item.
Book of Virtues: Spawns tiny skull wisps on the inner ring. The wisps fire bones and spawn friendly Bonies when destroyed. The book will summon wisps regardless of whether or not there were enemies killed in the current room, and the ring of wisps is close enough to Isaac to be inside the ring of bone orbitals Book of the Dead makes.
Mystery Egg - Spawn three charmed enemies in the same room.
Concept art for "Reanimate" (misspelled as "Reanimte"), an early version of Book of the Dead, on the right side along with other Booster Pack items and trinkets, by Edmund McMillen.
The Book of the Dead has been added in Booster Pack #5, after the initial release of the DLC.
The Book of the Dead is a collection of ancient Egyptian funerary texts made out of papyrus, consisting of magic spells intended to assist a soul's journey through the Duat (underworld) and into the afterlife.
The quote "Rise from the Grave" is a reference to the beginning screen of the video game Altered Beast.