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Large ooze, unaligned

Armor Class 9
Hit Points 51 (6d10 + 18)
Speed 10 ft., swim 10 ft.

20 (+5) 8 (-1) 17 (+3) 1 (-5) 10 (+0) 3 (-4)

Skills Stealth +1
Senses blindsight 60 ft. (blind beyond this radius), passive Perception 10
Damage Resistances fire
Damage Immunities acid, psychic
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, prone
Challenge 2 (450 XP)

Special Traits

  • Acid. A mudbog secretes a digestive acid that quickly dissolves organic material, but not metal or stone. A creature that attacks the mudbog takes 3 (1d6) acid damage. Any wood or other organic material that touches the mudbog is pitted. Wooden weapons suffer a cumulative -1 penalty to damage rolls made with it unless it is magical. When this penalty reaches -5, the weapon is destroyed.
  • Amorphous. The ooze can move through a space as narrow as 1 inch wide without squeezing.
  • False Appearance. The mudbog, while not moving, is indistinguishable from a muddy puddle.


  • Engulf. The mudbog moves up to its speed. While doing so, it can enter Medium or smaller creatures’ spaces. Whenever the mudbog enters a creature’s space, the creature must make a DC13 Dexterity saving throw. On a successful save, the creature can choose to be pushed 5 feet back or to the side of the mudbog. A creature that chooses not to be pushed suffers the consequences of a failed saving throw. On a failed save, the creature is engulfed and the mudbog enters the creature’s space. The creature takes 10 (3d6) acid damage. The engulfed creature can’t breathe, is restrained, and takes 21 (6d6) acid damage at the start of each of the ooze’s turns. When the mudbog moves, the engulfed creature moves with it. An engulfed creature can try to escape by taking an action to make a DC13 Strength check. On a success, the creature escapes and enters a space of its choice within 5 feet of the ooze.


What you originally thought was a patch of muddy water reveals itself to be a protoplasmic life-form resembling a giant brownish-black amoeba.

Mudbogs are strange, slow-moving, pudding-like creatures that dwell in swamps, fens, and wetlands. Situated comfortably in its hole along well-traveled paths, a mudbog is likely to be mistaken for a patch of muddy water or a wet spot in the road. Creatures attempting to simply walk over or through the “mud puddle” find themselves stuck fast and, worse yet, being consumed by the hungry ooze.

A mudbog doesn’t really attack its opponents; its method of getting a meal is strictly passive. However, once a meal stumbles into its protoplasmic body, the mudbog is determined not to let it escape. They are brownish in color, resembling nothing more than brackish mud.

These monsters use their coloration to their best advantage and use their acidic bodies to dig a hole, usually several feet deep, in which to lie in wait for a meal. The average mudbog is roughly 10 feet across and 3 feet deep.

A mudbog lacks the intelligence to collect treasure. However, the possessions of its victims can always be found in a heap at the bottom of the hole it has chosen as its home. Actually getting to the treasure involves somehow removing the mudbog from its hole.

Section 15: Copyright Notice

Tome of Horrors © 2018, Frog God Games, LLC; Authors: Kevin Baase, Erica Balsley, John “Pexx” Barnhouse, Christopher Bishop, Casey Christofferson, Jim Collura, Andrea Costantini, Jayson ‘Rocky' Gardner, Zach Glazar, Meghan Greene, Scott Greene, Lance Hawvermale, Travis Hawvermale, Ian S. Johnston, Bill Kenower, Patrick Lawinger, Rhiannon Louve, Ian McGarty, Edwin Nagy, James Patterson, Nathan Paul, Patrick N. Pilgrim, Clark Peterson, Anthony Pryor, Greg Ragland, Robert Schwalb, G. Scott Swift, Greg A. Vaughan, and Bill Webb

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