Black Patch

Large ooze, unaligned

Armor Class 7
Hit Points 153 (18d10 + 54)
Speed 0 ft., swim 40 ft.

18 (+4) 5 (–3) 16 (+3) 4 (–3) 6 (–2) 1 (–5)

Skills Stealth +3
Damage Resistances cold
Damage Immunities acid, poison
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, poisoned, prone
Senses blindsight 120 ft. (blind beyond this radius), passive Perception 8
Challenge 6 (2,300 XP)
Proficiency Bonus +3


  • Amphibious. The black patch can breathe air and water.
  • Eldritch Luminance. When a creature that can see the black patch starts its turn within 90 feet of the ooze, the black patch can force it to make a DC 15 Wisdom saving throw if the ooze isn’t incapacitated and can see the creature. On a failure, the creature is mesmerized for 1 minute. A mesmerized creature that is more than 5 feet away from the black patch must move on its turn toward the ooze by the most direct route, trying to get within 5 feet. It doesn’t avoid opportunity attacks, but before moving into damaging terrain, such as lava or a pit, and whenever it takes damage from a source other than the ooze, the target can repeat the saving throw. A mesmerized target can also repeat the saving throw at the end of each of its turns, ending the effect on itself on a success. If a creature’s saving throw is successful or the effect ends for it, the creature is immune to the black patch’s Eldritch Luminance for the next 24 hours.
  • Flowing Form. The black patch can enter a hostile creature’s space and stop there. It can move through a space as narrow as 1 inch wide without squeezing.
  • Ooze Nature. The black patch doesn’t require sleep.


  • Multiattack. The black patch makes two Pseudopod attacks. It can replace one attack with a use of Viscid Suffocation.
  • Pseudopod. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit: 7 (1d6 + 4) bludgeoning damage plus 13 (3d8) acid damage.
  • Viscid Suffocation. One creature in the black patch’s space must make a DC 15 Dexterity saving throw or take 18 (4d8) acid damage, and the black patch attaches to it, coating the creature and its equipment. While the black patch is attached to it, the creature’s speed is halved, it can’t breathe, and it takes 9 (2d8) acid damage at the start of each of its turns. In addition, if the creature is in the water, it has disadvantage on ability checks to swim or stay afloat. The black patch can devour flesh quickly, but its acid doesn’t harm metal, wood, or other similar objects or creatures without flesh. The black patch can detach itself by spending 5 feet of its movement. A creature, including the target, can take its action to detach the black patch by succeeding on a DC 15 Strength check.


A large patch of an odd, black substance floats on the water. Its glossy sheen catches the light in a shimmer of color as the inky black substance drifts ever-so-slowly upon the tide.

Black patch is a bizarre swamp ooze that has left most who studied it—from a safe distance—baffled by its origins.

Abstruse Lurker. At first glance, black patch resembles a grotesque specimen of pond scum. Casual inspection of its dark surface, however, reveals a psychedelic eldritch luminance within the tenebrous folds of its slimy mass—a myriad of swirling colors that perpetually spiral in a maddening dance.

Insatiable Hunger. A black patch stalks its prey slowly and silently from a distance. Since it can’t leave the water, this semi-sentient aquatic ooze is forced to take advantage of its terrain to help it scavenge or hunt. Its digestive acid dissolves flesh and bone quickly but has no effect on other substances, such as wood and metal.

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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