Gibbering Mouther 5e Guide
Medium Aberration, Neutral
At a Glance
CR
2
Type
Aberration
Size
Medium
Alignment
Neutral
AC
9
HP
67 (9d8 + 27)
Speed10 ft., swim 10 ft.
Ability Scores
str
10
+0
dex
8
-1
con
16
+3
int
3
-4
wis
10
+0
cha
6
-2
Key Abilities
| Ability | Description |
|---|---|
| Gibbering | Each creature that starts its turn within 20 ft. and can hear the mouther must succeed on a DC 10 Wisdom save or be unable to take reactions and use movement randomly. |
| Aberrant Ground | The ground within 10 ft. is doughlike difficult terrain. Each creature that starts its turn there must succeed on a DC 10 Strength save or have its speed reduced to 0. |
| Multiattack | One bite attack. If it hits, the target takes 5d6 piercing and must succeed on a DC 10 Strength save or be knocked <a href="/rules/conditions/prone-condition-5e/">prone</a>. |
How to Run This Monster
The gibbering mouther is a slow horror that turns the ground to mush and drives enemies mad with its incessant babbling. It oozes toward prey, trapping them in difficult terrain while its gibbering prevents coherent thought. It absorbs prey into its mass of eyes and mouths.
Encounter Ideas
Use the mouther in tight dungeon corridors where its slow speed doesn't matter and creatures can't easily escape its auras. The horror factor is key — describe the mass of eyes, mouths, and gibbering voices. It should feel like encountering a thing that shouldn't exist. Works great in aberration-themed dungeons near the Underdark.
Loot
The mouther has no treasure, but whatever it consumed can sometimes be found in its remains: 1d6 gp in coins, bones, and fragments of equipment.
Common Mistakes
Common Mistake
Forgetting Aberrant Ground — it traps creatures within reach
Common Mistake
Not describing the horror of the gibbering — it's a madness-inducing sound
Common Mistake
Making the encounter too easy by fighting in open terrain
DM Tips
DM Tip
Gibbering mouthers are perfect Lovecraftian horror encounters
DM Tip
Describe the babbling as fragments of speech from consumed victims
DM Tip
Use them in tight spaces where their slow speed doesn't matter
Frequently Asked Questions
Sources & Further Reading
- Gibbering Mouther — D&D 5e Wikidot — Full stat block
- Gibbering Mouther — D&D Beyond — Official monster reference
- Gibbering Mouther — Roll20 Compendium — Structured stat block