As the tome is opened, a blob of ink splashes toward the reader’s eyes, followed by mischievous giggles.

For those wary of prying eyes, a tiny construct made of ink can keep private journals, records of magical runes, or discoveries safe.

Tiny Guards. Created by wizards fearful of having their research stolen, bookkeepers are ink constructs bound to a designated book. They provide protection not just from unwanted intrusion but also from physical damage. The bookkeeper can move on its own when needed, but it spends most of its time hiding within the book it is assigned to guard.

Alarm. As long as the creator is on the same plane as the book, it is mentally alerted if the book is opened by anyone other than it. The book also shrieks if handled by anyone other than the creator. The creator does not set off any wards or alarms when opening its own book.

Construct Nature. A bookkeeper doesn’t require air, food, drink, or sleep.

Bookkeeper

Tiny construct, unaligned
Armor Class 12
Hit Points 5 (2d4)
Speed 20 ft., fly 30 ft. (while within the book)

STR	DEX	CON	INT	WIS	CHA
8 (-1)	14 (+2)	10 (+0)	6 (-2)	8 (-1)	3 (-4)

Skills Perception +1, Stealth +4
Damage Resistances bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities either cold or fire (designated at the time of the bookkeeper’s creation), poison, psychic
Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned
Senses blindsight 60 ft. (blind beyond this radius), passive Perception 11
Languages understands the languages of its creator but can’t speak
Challenge 1/8 (25 XP)

Between the Lines. As a bonus action while within 30 feet of its book, the bookkeeper can hop inside its book. While inside its book, the bookkeeper has a flying speed of 30 feet and is indistinguishable from ink on a page.

Book Bound. A bookkeeper makes all attacks, saving throws, and skill checks with advantage when its creator is within 60 feet of its book. The bookkeeper’s hp maximum is reduced by 1 for every minute it is further than 60 feet from its book. When its hp maximum reaches 0, it dies. If its creator dies, the bookkeeper can be convinced to pass ownership of the book to a new creature if the creature succeeds on a DC 13 Charisma check. The new owner becomes the bookkeeper’s new “creator” and inherits the bookkeeper along with the book.

Disintegrate. When the bookkeeper dies, the book it is bound to is also destroyed.

Actions

Ink Splash. Ranged Weapon Attack: +4 to hit, range 20 ft., one target. Hit: 3 (1d6) poison damage and the target must succeed on a DC 13 Dexterity saving throw or be blinded until the end of its next turn.

Bite. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: 1 piercing damage plus 1 poison damage.

Elusive Pages. While inside its book, the bookkeeper magically turns its book invisible until it attacks, or until its concentration ends (as if concentrating on a spell). The bookkeeper is also invisible while inside the invisible book

Alternate Traits and Actions

The following changes allow GMs to alter a bookkeeper without modifying its challenge rating.

Creator’s Mark. Melee Weapon Attack: +4 to hit, reach 5 ft., one target. Hit: The bookkeeper marks the target with an invisible rune, which it and its creator can see. The mark can be removed with a dispel magic or similar magic.

The bookkeeper loses its bite attack.

Dual Binding. The bookkeeper is attuned to two books rather than a single tome. It can use its Between the Lines trait to jump between books provided they are within range of each other. Its hp maximum reduction from its Book Bound trait only applies if it is farther than 60 feet from both books. Both books the bookkeeper are bound to are destroyed when it dies.

Stretching the bookkeeper’s magic across two books gives it the Antimagic Susceptibility trait:

• Antimagic Susceptibility. The bookkeeper is incapacitated while in an area of an antimagic field. If targeted by dispel magic, the bookkeeper must succeed on a Constitution saving throw against the caster’s spell save DC or fall unconscious for 1 minute.

Nauseating Ink. Ranged Weapon Attack: +4 to hit, range 20 ft., one target Hit: 3 (1d6) poison damage, and the target must succeed on a DC 13 Constitution save or be poisoned until the end of its next turn.

The bookkeeper loses its Ink Splash action.

Possess Reader (Recharges after a Long Rest). The fiendish bookkeeper treats its book as a container for a magic jar spell. It can possess a humanoid per the magic jar spell (save DC 9) if the humanoid moves within 60 feet of it. The bookkeeper can only possess a target for 10 minutes before it must return to its book. A DC 13 Wisdom (Perception) check notices ink flowing through the whites of the possessed creature’s eyes, and a DC 13 Intelligence (Arcana) check discovers the possession.

The fiendish bookkeeper loses its X Marks the Spot trait.

Spell Attunement (Recharge 4–6). The bookkeeper has access to a 1st-level spell within its book. Its spellcasting ability is Wisdom (spell save DC 9, +1 to hit with spell attacks). It can use an action to innately cast the spell, requiring no material components.

The bookkeeper loses its Elusive Pages action.