Gibbering Arm

Small aberration, chaotic neutral

Armor Class 12
Hit Points 15 (2d10 + 4)
Speed 15 ft., burrow 10 ft.

18 (+4) 13 (+1) 15 (+2) 1 (-5) 10 (+0) 3 (-4)

Senses blindsight 10 ft., passive Perception 10
Challenge ¼ (50 XP)


  • Symbiotic Bond. The gibbering arm consumes a willing or unconscious creature’s arm. That creature becomes its host. The creature’s arm is replaced by the gibbering arm and cannot wield shields or weapons, including two-handed weapons, but it can lift, drop, hold, push, and grasp things. The arm can perform the somatic spell components of spells. The arm acts as a shield, granting its host a +2 bonus to AC. Additionally, the host’s Strength score increases to 18 if it is less than 18.


  • Bite. Melee Weapon Attack: +6 to hit, reach 5 ft., one creature. Hit: 7 (1d6 + 4) piercing damage. A creature hit by this attack is grappled (escape DC 14). Until this grapple ends, the creature is restrained, and the gibbering arm can’t bite another target. If the creature remains grappled in this way for 1 minute, it becomes the gibbering arm’s host. A lost limb can be restored by effects such as the regenerate spell.


Gibbering arms have dense wormlike bodies of liquified flesh covered with sets of eyes and mouths from different creatures they have consumed, with each end of their tubular form leading to a toothed maw surrounded by splayed tentacles. They are terrifying to behold, and maddening to play host to.

Mouths to Feed. Gibbering arms have only one goal: to feed. Though they prefer flesh found in the wild, these creatures readily devour organic and inorganic material alike, seeming sated only in fleeting moments while feeding. Gibbering arms can survive in the wild independently, hunting like great worms, but each seeks to bond with a host to fulfil their true potential for consumption. If a gibbering arm is found without a host, it is likely because something did not survive the attachment process, which involves the aberration consuming one of its prey’s arms and latching itself to them at the shoulder.

Leeching off of their host’s metabolism and driving them to unendingly seek sustenance for the both of them, gibbering arms usually drain and eventually devour weaker hosts, and only the strong can withstand them.

Whispers of the Past. When a gibbering arm consumes a creature’s body it is absorbed into its mass, the creature’s mouth and eyes appearing on the arm within a few hours of consumption. Though their bodies are consumed, the psychic remnants of the mouther’s victims remain; the eyes of these creatures often appear to be in a state of confusion, pain, anger, or terror, their mouths whispering incoherently. Gibbering arms without hosts will grow into gibbering mouthers after consuming enough food to undergo the metamorphosis.

Alien Influence. The gibbering arm gives its host the following flaw: “My hunger is insatiable, and the hungrier I get the louder my arm’s whispers become.”

Section 15: Copyright Notice

Zargoth’s Tome of Familiars, Copyright 2021, Arcana Games, LLC.

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