Demon Lord of Rats

Family: Demons

Medium fiend (demon), chaotic evil

Armor Class 16
Hit Points 172 (23d8 + 69)
Speed 30 ft., swim 20 ft.

12 (+1) 22 (+6) 17 (+3) 21 (+5) 20 (+5) 10 (+0)

Saving Throws Dexterity +11, Constitution +8, Intelligence +10
Skills Insight +10, Perception +10, Stealth +11
Damage Resistances cold, lightning
Damage Immunities fire, necrotic, poison
Condition Immunities poisoned
Senses darkvision 120 ft., truesight 60 ft., passive Perception 20
Languages Abyssal, Common, Void Speech, telepathy 120 ft.
Challenge 13 (10,000 XP)

Special Traits

  • Fire Dancer. Whenever the Demon Lord of Rats is subjected to fire or necrotic damage, he takes no damage and instead is unaffected by spells and other magical effects that would impede his movement. This trait works like the freedom of movement spell, except it only lasts for 1 minute.
  • Quick Escape. As a bonus action, the Demon Lord of Rats teleports, along with any equipment he is wearing or carrying, up to 60 feet to an unoccupied space he can see.
  • Legendary Resistance (3/day). If the Demon Lord of Rats fails a saving throw, he can choose to succeed instead.


  • Multiattack. The Demon Lord of Rats makes two Soul Bite attacks or three Necrotic Flame attacks.
  • Soul Bite. Melee Weapon Attack: +11 to hit, reach 5 ft., one target. Hit: 15 (2d8 + 6) piercing damage plus 7 (2d6) necrotic damage.
  • Necrotic Flame. Ranged Spell Attack: +10 to hit, 120 ft., one target. Hit: 13 (3d8) necrotic damage.


  • Soul Devouring. When the Demon Lord of Rats or a rattok demon within 120 feet of the Demon Lord of Rats reduces a creature to 0 hp, the demon lord devours that creature’s soul. The Demon Lord of Rats gains 19 (3d12) temporary hp and the creature must succeed on a DC 18 Constitution saving throw or suffer two failed death saving throws.

Legendary Actions

The demon lord can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature’s turn. The Demon Lord of Rats regains spent legendary actions at the start of his turn.

  • Soul Bite. The Demon Lord of Rats uses his soul bite attack.
  • Stumble. The Demon Lord of Rats commands a rat to dash under the feet of a creature within 60 feet, causing it to stumble. The creature must succeed on a DC 15 Dexterity saving throw or it drops whatever it is holding and falls prone.
  • Plague Breath (Costs 2 Actions). The Demon Lord of Rats surrounds himself with hideous vapors from his pipe, a screeching, pestilent mix of damned souls and poison gas. The gas spreads around corners, and its area is lightly obscured. Each creature that starts its turn within 10 feet of the Demon Lord of Rats must make a DC 15 Constitution saving throw. On a failure, the creature takes 16 (3d10) necrotic damage and is poisoned. On a success, the creature takes half the damage and is not poisoned. The gas lasts until the Demon Lord of Rats uses this legendary action again or until the Demon Lord of Rats dies. Rats, rattok demons, wind demons, and the Demon Lord of Rats are immune to the effects of Plague Breath. The Demon Lord of Rats has a pipe of cracked bone inlaid with golden glyphs, a pipe of glowing green jade that shines in the night, a pipe of black glass etched with blasphemous demonic triumphs, and (richest of all) a ruby pipe with mithral inlay in various disturbing patterns, a work of pure chaos artistry. All four of these pipes are associated with a particular gaseous magical effect: fog cloud (bone pipe), cloudkill (jade pipe), cloud of daggers (black glass pipe), and incendiary cloud (ruby pipe). A creature smoking the pipe can cast the associated spell as a bonus action 1/day.


Puffing on his faintly screaming pipe, the foul creature seemed almost contemplative as he disemboweled the humans, one by one. The air around him was thick with plague, with nibbling decay, and with the greasy shine of hideous dreams. The demon lord is an upright and partly-humanoid large, red-eyed rat. His grey-white fur is sometimes spattered with offal and flecked with blood; other times, he is groomed constantly by swarms of ordinary rats. The Demon Lord of Rat’s tail is tipped with a strange greenish fire. His front paws are long-fingered in the manner of rats, fully capable of holding and manipulating wands, scrolls, and other objects. He has long gold incisors, a short snout, and large ears (often ornamented with black or golden rings). He often smokes a magical pipe filled with mortal souls, drawing necrotic energy from this unhallowed vessel.

Cunning and Malicious. The Demon Lord of Rats finds human weakness amusing and delights in cruelty. While still given to unbridled destruction, he is sometimes more cunning than other demon lords. He is able to destroy a crop or a city with equal joy. He justifies this as “vengeance for my brethren”-for all rats are his worshippers and slaves.

Devourer of Souls. The Demon Lord of Rat’s power comes in part from eating entire legions of mortal souls, and he dreams of attaining godhood through the devouring of demons. Rattok demons are said to be his creations.

Lord of Shadows. The Demon Lord of Rats keeps a vast network of spies in the mortal world. All red-eyed rats are his servants, chittering their knowledge of blood, sacrifice, and misery to their dark lord. The Demon Lord of Rats uses this information to give his followers greater reach, to destroy granaries, to starve entire nations, and to spread disease and misery everywhere his long-fingered claws reach.


The Demon Lord of Rat’s lair is a vast realm of tunnels and dank caverns with thousands, if not millions, of rats, ratfolk, rattok demons and other horrors, a noisy place of constant squeals and skittering filled with the rank smells of blood, offal, and sweat. It is filled with snarling creatures preying on one another in its narrow, bone-strewn passages. Its only illumination comes from unholy sigils and territorial markings made in multi-colored, pale luminous ink.

Lair Actions

On initiative count 20 (losing initiative ties), the Demon Lord of Rats can take a lair action to cause one of the following effects; he can’t use the same effect two rounds in a row:

  • A cloud of filth and the smell of rotting garbage fills the lair. Each creature within 60 feet of the Demon Lord of Rats must succeed on a DC 15 Constitution saving throw or be poisoned until initiative count 20 on the next round.
  • Rats swarm together into miniature boulders and drop from the ceiling, striking up to three creatures beneath them that the Demon Lord of Rats can see within 120 feet of him. The Demon Lord of Rats makes one ranged attack roll (+11 to hit) against each target. On a hit, the target takes 10 (3d6) bludgeoning damage and has disadvantage on concentration checks until initiative count 20 on the next round as the rats scamper down the target.
  • A swarm of ghostly rattok demons fills a 20-foot-radius sphere at a point the Demon Lord of Rats chooses within 120 feet. The swarm of ghosts spreads around corners and remains until the Demon Lord of Rats dismisses it as an action, uses this lair action again, or dies. The swarm is lightly obscured, and its area is difficult terrain. A creature in the swarm when it appears or that ends its turn in the swarm must make a DC 18 Dexterity saving throw, taking 39 (6d12) necrotic damage on a failed save, or half as much damage on a successful one.
Section 15: Copyright Notice

Creature Codex. © 2018 Open Design LLC; Authors Wolfgang Baur, Dan Dillon, Richard Green, James Haeck, Chris Harris, Jeremy Hochhalter, James Introcaso, Chris Lockey, Shawn Merwin, and Jon Sawatsky.

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