Rotsam Swarm

Large swarm of Tiny oozes, unaligned

Armor Class 9
Hit Points 142 (15d10 + 60)
Speed 10 ft., swim 30 ft.

19 (+4) 8 (-1) 18 (+4) 1 (-5) 9 (-1) 6 (-2)

Damage Resistances bludgeoning, piercing, slashing
Damage Immunities necrotic
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, grappled, paralyzed, petrified, prone, restrained, stunned
Senses blindsight 60 ft. (blind beyond this radius), passive Perception 9
Challenge 6 (2,300 XP)


  • Bog Rot. As the rotsam.
  • Spider Climb. As the rotsam.
  • Swarm. The swarm can occupy another creature’s space and vice versa, and the swarm can move through any opening large enough for a Tiny rotsam. The swarm can’t regain hp or gain temporary hp.


  • Diseased Bites. Melee Weapon Attack: +7 to hit, reach 0 ft., one creature in the swarm’s space. Hit: 10 (4d4) piercing damage plus 21 (6d6) necrotic damage, or 5 (2d4) piercing damage and 10 (3d6) necrotic damage if the swarm has half of its hp or fewer. The target must make a DC 15 Constitution saving throw or contract a disease (see the Bog Rot trait).


A quivering glob wraps around a corpse’s arm. Though the corpse is already decaying, the glob seems to accelerate the rot.

Expediter of Decay. The rotsam feeds on rotting flesh, encouraging decay in already rotten corpses and initiating decay in previously preserved corpses. Unfortunately, the rotsam can affect living tissue just as well and makes no distinction between the two.

Leechlike Underwater Dwellers. Rotsams attach to their prey like leeches, but they are considerably more difficult to remove than ordinary leeches.

Favored of Rot Cults. Cultists devoted to deities of disease, death, and decay “raise” rotsams for use in their sacrificial rituals.

Ooze Nature. A rotsam doesn’t require sleep.

Section 15: Copyright Notice

Tome of Beasts 2. © 2020 Open Design LLC; Authors Wolfgang Baur, Celeste Conowitch, Darrin Drader, James Introcaso, Philip Larwood, Jeff Lee, Kelly Pawlik, Brian Suskind, Mike Welham.

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