Codex Umbra

"I'm so sorry Charlie."

- Maxwell

The Codex Umbra is a book on dark magics that Maxwell starts the game with. When used, it sacrifices 15 health and 55 of maximum sanity to spawn a Shadow Puppet clone of Maxwell. It has infinite durability and requires 2 Nightmare Fuel to be used. For each puppet active, Maxwell's maximum sanity is reduced, similar to how Meat Effigies reduce maximum health. A maximum of 3 puppets can be active at one time and each one will disappear 2.5 days after it was summoned.

Shadow Puppets
A Shadow Puppet is a Shadow Creature version of Maxwell that does his bidding. While puppets are active, they will aid Maxwell in combat as well as also aiding him in cutting trees and mining rocks. Unlike other followers, passive mobs will not run from them, making it easy to farm Morsels and Feathers from Rabbits and Birds. However, they have low health and will die quickly in combat against more able foes. On death the player gains back the 55 max sanity from the puppet.

To keep a good supply of Nightmare fuel for the puppets it's recommended to farm Beardlings with them. 3 puppets summoned will keep you always below the threshold in which Beardlings spawn making it easy. Otherwise you can keep eating raw morsels dropped by birds to decrease your sanity. Also the puppets will easily kill Butterflies and you can eat Butterfly Wings to regain the health it cost to summon them.

Trivia

 * Codex Umbra means "book of shadows".
 * Unlike other character-specific items, the Codex Umbra doesn't disappear when DebugSpawned by another character. The character is unable to use it, though.
 * Wickerbottom can use the Codex Umbra, but the book glows yellow instead of black, and her summoned minions are invisible.
 * The footsteps of the puppets make a faint warping sound.
 * It is possible for the Codex Umbra to be set alight and burn into ashes. The book will re-appear in Maxwell's inventory upon re-loading the world.
 * Maxwell says ``I`m so sorry Charlie`` when examining the book because Charlie (Night Monster) was his assistant,he (Maxwell) will...ahh long story look Charlie (Night Monster)!