Large aberration, chaotic evil

Armor Class 12
Hit Points 105 (14d10 + 28)
Speed 50 ft.

18 (+4) 14 (+2) 15 (+2) 11 (+0) 17 (+3) 16 (+3)

Damage Immunities necrotic, poison
Condition Immunities charmed, paralyzed, poisoned
Senses blindsight 120 ft. (blind beyond this radius), passive Perception 13
Languages Celestial, Elvish, Sylvan, telepathy 60 ft.
Challenge 5 (1,800 XP)
Proficiency Bonus +3


  • Magic Evasion. If the nullicorn is subjected to a spell or magical effect that allows it to make a saving throw to take only half damage, the nullicorn instead takes no damage if it succeeds on the saving throw, and only half damage if it fails.
  • Limited Magic Immunity. At the end of the nullicorn’s turn, any spell or magical effect with a duration that is affecting the nullicorn, such as hold monster or mage armor, immediately ends.
  • Magic Resistance. The nullicorn has advantage on saving throws against spells and other magical effects.
  • Nullifying Blight. A creature infected with this disease manifests symptoms 1d4 hours after infection, which include fatigue, light-headedness, and blurry vision. When an infected creature casts a spell or activates a magic item, an itchy rash appears and spreads as more magic is used. Until this disease is cured, when the infected creature starts its turn wielding or wearing a magic item and each time it casts a spell or activates a magic item, it loses 5 (2d4) hp. At the end of each long rest, the infected creature must make a DC 13 Constitution saving throw. On a failure, the hp the creature loses each time it uses magic increases by 2 (1d4). A creature that succeeds on three saving throws recovers from the disease.
  • Sense Magic. The nullicorn senses magic within 120 feet of it at will. This trait otherwise works like the detect magic spell but isn’t itself magical.


  • Multiattack. The nullicorn makes two Hooves attacks and one Void Horn attack.
  • Hooves. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 11 (2d6 + 4) bludgeoning damage.
  • Void Horn. Melee Weapon Attack: +7 to hit, reach 5 ft., one target. Hit: 8 (1d8 + 4) force damage, and the target must succeed on a DC 13 Constitution saving throw or contract the nullifying blight disease (see the Nullifying Blight trait).
  • Spread Blight (Recharge 5–6). The nullicorn’s Void horn flashes and emits a brief ripple of darkness. Each creature within 20 feet of the nullicorn must make a DC 13 Constitution saving throw. On a failure, a creature takes 18 (4d8) necrotic damage and contracts the nullifying blight disease (see the Nullifying Blight trait). On a success, a creature takes half the da half the damage and doesn’t contract the disease.


Only scraps of its unicorn’s once-pristine hide now remain, dissolving and reappearing at random, exposing muscle, tissue, and bone tainted by wild magic. Its dark horn winks in and out of existence, flickering with dark magic. A void remains where its eyes once were.

Perhaps nothing is as profane as a corrupted unicorn. When a unicorn is trapped within eldritch wastelands, it is worn down, its flesh is altered and burned away, and its magic is snuffed out and corrupted into something maddening and vile, creating a nullicorn.

Eldritch Dampening. The transformation of a nullicorn’s physical form has caused its very essence to repulse magic. Like oil and water, the nullicorn and eldritch energies do not mix. This dampening force is so potent, proximity to a nullicorn can infect a creature with the taint of its resistance.

Magic Hatred. Nullicorns despise magic and all things magical, raging at the loss of the power they once possessed. Though a nullicorn will combat anything in its path, it seeks and attempts to destroy those who can wield magic, either by spell or enchanted item.

Section 15: Copyright Notice

Tome of Beasts 3 © 2022 Open Design LLC; Authors: Eytan Bernstein, Celeste Conowitch, Benjamin L. Eastman, Robert Fairbanks, Scott Gable, Basheer Ghouse, Richard Green, Jeremy Hochhalter, Jeff Lee, Christopher Lockey, Sarah Madsen, Ben Mcfarland, Jonathan Miley, Kelly Pawlik, Sebastian Rombach, Chelsea Steverson, Brian Suskind, Mike Welham

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