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Murmuring Worm


AC 16 (natural armor)

HP 195 (17d12 + 85; bloodied 97)

Speed 40 ft., burrow 20 ft., climb 40 ft., swim 40 ft.

Proficiency +4; Maneuver DC 17

Damage Immunities psychic

Condition Immunities prone

Senses darkvision 60 ft., tremorsense 60 ft., passive Perception 12


Amphibious. The worm can breathe air and water.

Locate Mind. The worm is aware of the location and relative intelligence of all creatures with Intelligence scores greater than 3 within 500 feet.

Maddening Murmurs. The worm babbles constantly. A non-aberrant creature that starts its turn within 30 feet and can hear its murmurs makes a DC 14 Intelligence saving throw . On a failure, the creature takes 10 (3d6) psychic damage and is confused until the start of its next turn.


Multiattack. The worm constricts once and attacks once with its bite.

Constrict. Melee Weapon Attack: +9 to hit, reach 5 ft., one creature. Hit: 21 (3d10 + 5) bludgeoning damage. The target is grappled (escape DC 17) and restrained while grappled.

Bite. Melee Weapon Attack: +9 to hit, reach 5 ft., one creature. Hit: 21 (3d10 + 5) piercing damage. If the target is killed by this attack, the worm eats its head.


Mental Summons. One creature with an Intelligence score greater than 3 within 120 feet makes a DC 16 Wisdom saving throw . On a failure, it uses its reaction to move up to its Speed towards the worm by the shortest route possible, avoiding hazards but not opportunity attacks . This is a magical charm effect.


The worm approaches the creature with the highest Intelligence score while using its Mental Summons on that creature. On the way to its intended victim, it attacks any creature next to it, targeting the smartest creature available on its turn. It fights to the death, retreating only if it can’t reach any prey.

Legends and Lore

With an Arcana or Religion check, characters can learn the following:

DC 10 Although none know for certain, many scholars believe gibbering mouthers are horrible abominations from another reality.

DC 15 A gibbering mouther’s babble can drive even the strong-willed mad.

DC 20 The presence of a gibbering mouther warps reality itself, transforming the ground around it into a sucking mire.


A gibbering mouther that gorges on enough bodies grows to become a murmuring worm: a pink glistening worm dozens of feet long and covered with humanoid mouths. The murmuring worm pursues the most intelligent prey it can catch, consuming the head and leaving the body intact.


1 Attacks on sight

2 Attacks on sight while shouting, "No," "Don't hurt me," "Glad to meet you," and other non sequiturs

3 Focused on warping its environment (perhaps making a new tunnel or sculpting a copy of itself); only attacks if you approach or interfere

4 Acting nonsensically: talking to objects, trying to climb up walls, etc.


1 Distant babbling voices

2 Rocks and other solid objects are warped or crumbling

3 A random character gets a sudden headache, or telepathically overhears babbling voices

4 A mouth appears on a solid object, yells a few words, and vanishes


Gibbering mouthers appear in laboratories, eldritch dungeons, and places where the walls of reality are thin.

CR 0–2 gibbering mouther

CR 3–4 2 gibbering mouthers ; gibbering mouther with grick or mimic

CR 11–16 murmuring worm

Monster Type Description

Aberrations are unnatural beings that don’t belong to this plane of existence. Many aberrations are telepathic and use a mental power known as psionic power instead of magic. An aboleth is an aberration.