This site is games | books | films


Gibbering Mouther

Gibbering mouthers were not natural creaturesThis horrid mass of eyes, mouths, and formless flesh stares in all directions, its countless maws yammering ceaselessly.

Disgusting, loathsome, and hungry—these are the only words that properly describe the gibbering mouther. A foul beast that lurks in underground caves, sewers, and nightmares, mouthers have no societal, ecological or religious significance other than their ability to drive those that listen to them mad. Some scholars believe that gibbering mouthers are a lesser variant of the much more dangerous shoggoth, while others theorize they are a punishment by some powerful being or deity inflicted on those who have offended it.

Gibbering Mouther, Common

Family: Gibbering Mouther

Medium ravager (devastation), chaotic evil or unaligned

Armor Class 9
Hit Points 67 (9d8 + 27); Wound Threshold 17
Speed 10 ft., swim 10 ft.

10 (+0)8 (-1)16 (+3)3 (+4)10 (+0)6 (-4)

Condition Immunities grappled, prone, restrained
Senses darkvision 60 ft., tremorsense 60 ft., passive Perception 10
Languages Phantasm
Challenge 2 (450 XP)


  • Aberrant Ground. The ground in a 10-foot radius around the common mouther is doughlike difficult terrain. Each creature that starts its turn in that area must succeed on a DC 13 Strength saving throw or have its speed reduced to 0 until the start of its next turn.
  • Corrosive Fluids. After dealing a Wound or a critical hit to the common mouther, the weapon used is covered in corrosive fluids. Any non-magical weapon or armor under this effect, and which is not protected by an appropriate forging technique (such as dwarven forging), becomes fragile (see Adventurers, Equipment, Armory: Damaged Weapons and Armor).
  • Gibbering. The common mouther babbles incoherently while it can see any creature and isn’t incapacitated. Each creature that starts its turn within 20 feet of the common mouther and can hear the gibbering must succeed on a DC 10 Wisdom saving throw. On a failure, the creature can’t take reactions until the start of its next turn and rolls a d8 to determine what it does during its turn.
1 to 4The creature does nothing.
5 to 6The creature takes no action or bonus action and uses all its movement to move in a randomly determined direction.
7 to 8The creature makes a melee attack against a randomly determined creature within its reach or does nothing if it can’t make such an attack.


  • Multiattack. The common gibbering mouther makes one bite attack and, if it can, uses its Blinding Spittle.
  • BiteMelee Weapon Attack: +2 to hit, reach 5 ft., one creature. Hit: 17 (5d6) piercing damage. If the target is Medium or smaller, it must succeed on a DC 10 Strength saving throw or be knocked prone.
  • Blinding Spittle (Recharge 5-6). The common mouther spits a chemical glob at a point it can see within 15 feet of it. The glob explodes in a blinding flash of light on impact. Each creature within 5 feet of the flash must succeed on a DC 13 Dexterity saving throw or be blinded until the end of the mouther’s next turn.
  • Voracious Ingestion. A Small or smaller creature within 5 feet of the common mouther must succeed on a DC 13 Dexterity saving throw or be grappled (escape DC 10). Until this grapple ends, the creature is also restrained, and the common mouther can’t ingest another target. In addition, the creature takes 7 (2d6) bludgeoning damage at the end of each of the mouther’s turns. If a creature takes damage this way, apply the Corrosive Fluids effect to its armor.


The gibbering mouther is an animated, autonomous, Cankerous growth, capable of merging back into the morbid mass from which it came. It perpetually conjures ephemeral eyes, mouths, or other organs according to its immediate needs.

These creatures appear to be a large glob of animated mucus, dripping goo as they wander. Around them, the ground appears to be moving and reality, distorted. This effect is linked to the profound reality of Canker and its world-changing aspect-dissolving, deconstructing, and, finally, recomposing.

A gibbering mouther’s maximum size depends on that of the metastasis which gave birth to it. The most common ones, closer to the surface, can only generate medium sized gibbering mouthers; older, deeper ones can create monsters that are much larger and stronger, more dangerous and resilient. The gibbering mouther is a guardian dedicated to protecting the nest, and especially its vile heart: the beating growth.

The Devouring Horror

If you use this option, the gibbering mouther’s Voracious Ingestion is more dangerous and gains the following special features:

If a creature grappled by a gibbering mouther does not use its action to escape, it takes an additional 7 (2d6) bludgeoning damage, which is added to the other damage.

Wounds inflicted by Voracious Ingestion translate as complex fractures that render the affected limbs useless. If a leg were grabbed, it would appear almost crushed.

If the common gibbering mouther reduces a creature to 0 hit points, it can use Voracious Ingestion as a bonus action. When Voracious Ingestion is used on a creature that has dropped to 0 hit points, the body is destroyed in 3 rounds and can only be brought back to life by the true resurrection or wish spells.

Section 15: Copyright Notice

The Creatures Rulebook for the Fateforge Role-Playing Game Copyright © 2021 Studio Agate.

Gibbering Mouther CR 5

XP 1,600
N Medium aberration
Init +3; Senses all-around vision, darkvision 60 ft.; Perception +12


AC 19, touch 13, flat-footed 16 (+3 Dex, +6 natural)
hp 46 (4d8+28)
Fort +8, Ref +4, Will +5
Defensive Abilities amorphous; DR 5/bludgeoning; Immune critical hits, precision damage


Speed 10 ft., swim 20 ft.
Melee 6 bites +7 (1d4 plus grab)
Special Attacks blood drain, engulf (6d4 damage plus 2 Con damage, AC 13, hp 4), gibbering, ground manipulation, spittle (+6 ranged touch)


Str 10, Dex 17, Con 24, Int 4, Wis 13, Cha 12
Base Atk +3; CMB +3 (+7 grapple); CMD 16 (can’t be tripped)
Feats Weapon Finesse, Weapon Focus (bite)
Skills Perception +12, Swim +8; Racial Modifiers +4 Perception
Language all


  • All-Around Vision (Ex) A gibbering mouther sees in all directions at once. It cannot be flanked.
  • Amorphous (Ex) A gibbering mouther’s body is malleable and shapeless. It is immune to precision damage (like sneak attacks) and critical hits, and can move through an area as small as one-quarter its space without squeezing or one-eighth its space when squeezing.
  • Blood Drain (Ex) On a successful grapple check after grabbing, several of the creature’s mouths attach to its target. Each round it maintains its grapple, its mouths automatically deal 1d4 points of bite damage and 1 point of Constitution damage as it drains its victim’s blood.
  • Engulf (Ex) This ability functions as swallow whole, except for the following changes. An engulfed creature is trapped in the gibbering mouther’s body, where several of its mouths continue to feed and drain blood. A gibbering mouther can engulf only one foe of its size or smaller at a time. If an engulfed creature cuts its way free (the mouther’s damage reduction still applies to those inside), the mouther simply flows together again and can still use its engulf attack.
  • Gibbering (Su) As a free action, a gibbering mouther can emit a cacophony of maddening sound. All creatures other than gibbering mouthers within 60 feet must succeed on a DC 13 Will save or be confused for 1 round. This is a mind-affecting compulsion insanity effect. A creature that saves cannot be affected by the same mouther’s gibbering for 24 hours. The save DC is Constitution-based.
  • Ground Manipulation (Su) At will as a standard action, a gibbering mouther can cause stone and earth under its body to grow soft and muddy. The ground remains muddy for 1 minute after the mouther moves off of the location. A gibbering mouther can move through these areas with ease, but other creatures treat them as difficult terrain.
  • Spittle (Ex) Each round as a free action, a gibbering mouther can emit a stream of acidic spittle at one target within 30 feet. On a successful attack, the target is blinded for 1d4 rounds unless he succeeds on a DC 18 Fortitude save. The save DC is Constitution-based.


Environment any underground
Organization solitary
Treasure standard

Gibbering Mouther
Gibbering Mouther BY butchRbill
Scroll to Top