Swarm Assassin

Medium humanoid, lawful evil

Armor Class 13
Hit Points 33 (6d8 + 6)
Speed 30 ft.

12 (+1) 17 (+3) 13 (+1) 8 (-1) 15 (+2) 5 (-3)

Skills Perception +4, Stealth +5
Damage Resistances bludgeoning, piercing, and slashing
Condition Immunities charmed, frightened, paralyzed, petrified, stunned
Senses darkvision 120 ft., passive Perception 14
Languages Common
Challenge 2 (450 XP)
Proficiency Bonus +2


  • Swarm Weakness. The assassin takes double damage from area attacks.


  • Multiattack. The assassin makes two shortsword attacks.
  • Shortsword. Melee Weapon Attack: +5 to hit, reach 5 ft., one target. Hit: 6 (1d6 + 3) piercing damage. The target must succeed on a DC 11 Constitution saving throw or take 7 (2d6) poison damage and be poisoned until the end of its ne xt turn.
  • Discorporate. The assassin dissolves its humanoid shape, becoming a shapeless swarm of locusts, or returns to its assassin form. Its equipment falls to the ground in its current space. While discorporated, the assassin retains its statistics but can’t use its shortsword attack, speak, or manipulate objects, and it can move through a space as narrow as 1 inch wide without squeezing.


  • Reactive Sting. When a creature within 5 feet of the assassin hits it with a melee attack, insects erupt from the assassin and sting the attacker. The attacker must succeed on a DC 11 Constitution saving throw or take 7 (2d6) poison damage and be poisoned until the end of its next turn.


Attacks made against swarm assassins seem to pass through the creature ineffectively, leading many panicked adventurers to believe they are fighting a ghost or specter. Swarm assassins are all too happy to perpetuate such myths in order to mask their true nature and vulnerabilities.

Created by means of a powerful shadowy summoning ritual, a swarm assassin arrives on the Material Plane replete with an ominous black shortsword and billowing dark robes that obscure its features. Anyone unfortunate enough to catch a glimpse of the visage beneath the robes sees a swarming mass of insects where flesh should be. These insects are poisonous black locusts native to the Plane of Shadow, bound together in humanoid shape with powerful unholy magic.

Once summoned, a swarm assassin awaits orders from its summoner and carries out its duties to the best of its ability. Swarm assassins remain on the Material Plane until their orders are completed or for one moon cycle, whichever comes first. Once back on the Plane of Shadow, a swarm assassin discorporates into a humming mass of bugs that skitter to the plane’s dark corners.

Evil wizards occasionally summon swarm assassins to serve as their bodyguards, but more often, vile clerics summon these fiendish servants to deal with heretics or enemies of their order. Swarm assassins excel at tracking down their targets and typically do so under cover of night. They avoid civilized areas, though their basic level of intellect allows them to interact with unsuspecting individuals when necessary. Roadside innkeepers whisper of the disturbing hum that emanates from such occasional cloaked guests, who pay for information and rumors with the distinct dragon-stamped coinage of the Plane of Shadow.

A swarm assassin typically attacks its targets when they are alone or far from the nearest settlement.

It launches its assault from dark corners or bushes, weakening foes with poison before slipping back into the shadows, spreading out as a bug swarm, then reincorporating at a different spot on the battlefield and attacking once more.

Section 15: Copyright Notice

Battlezoo Bestiary (5E) © 2022, Skyscraper Studios, Inc.; Authors: William Fischer, Stephen Glicker, Paul Hughes, Patrick Renie, Sen.H.H.S., and Mark Seifter.

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