Gibbering mouthers were unnatural aberrations, nightmarish blobs of mouths and eyes.
These bizarre creatures appeared as large blobs composed entirely of mouths and eyes. When the eyes and mouths were closed, the gibbering mouther resembled a large lump of earth.
Gibbering mouthers were not natural creatures. Usually, they were the creation of foul sorcery. Some sages instead claimed that gibbering mouthers arose from sentient creatures that had died in places touched by the Far Realm.
Gibbering mouthers reproduced by asexual fission. They would split their amorphous bodies down the middle whenever they had consumed enough nutrients to support two bodies. The mouther would hide in a secure area while performing this process, since it could take up to four hours. Once split, the two mouthers would move away from each other.
Every victim consumed by a gibbering mouther added another mouth and pair of eyes to the mass of the beast's body. Only living prey would work for this.
Some sages believed that bringing two gibbering mouthers together would cause them to join, creating a larger mouther.
Gibbering mouthers liked to ambush prey by remaining still until their prey was within striking range.
The most vulnerable area on a gibbering mouther was the brain, which was located near the center of its mass and could move around, making it difficult to strike.
Gibbering mouthers could use a special babbling attack that had the same effect as the confusion spell. This attack assaulted potential prey every few moments, making it more difficult for them to resist.
Spit from a gibbering mouther would explode with a bright flash once it struck any surface, easily blinding targets for several minutes.
A gibbering mouther was able to attack with six different mouths at a time. Each mouth had a chance to latch on to the victim and begin draining their energy.
The ground around a gibbering mouther was turned into a thick liquid state, making it extremely difficult to assault the mouther at a close range.
In 1367 DR, during the Living Gem War, the wizard Shond Tharovin was cursed by the archmage Yoond Shalshymmyr and permanently changed into an immense (over twelve-miles-long) gibbering mouther, sacrificing his life to do so. Shond vowed revenge and left his city of Schamedar to enter the ocean. Shond eventually settled on the Singing Rocks in the Trackless Sea, where he planned the demise of his enemies.
These creatures were never found near others of their kind.
Gibbering mouthers were omnivorous creatures.
Swamps were their preferred habitat in the wild.
- Nigel Findley (August 1990). “The Ecology of the Gibbering Mouther”. In Roger E. Moore ed. Dragon #160 (TSR, Inc.), pp. 55–57.
- Mike Mearls, Jeremy Crawford, Christopher Perkins (2014-09-30). Monster Manual 5th edition. Edited by Scott Fitzgerald Gray. (Wizards of the Coast), p. 157. ISBN 978-0786965614.
- Mike Mearls, Stephen Schubert, James Wyatt (June 2008). Monster Manual 4th edition. (Wizards of the Coast), pp. 126–127. ISBN 978-0-7869-4852-9.
- Skip Williams, Jonathan Tweet, Monte Cook (July 2003). Monster Manual v.3.5. (Wizards of the Coast), p. 126. ISBN 0-7869-2893-X.
- Wolfgang Baur (1993). Assassin Mountain: Monstrous Compendium Pages. (TSR, Inc.). ISBN 9-781560-765646.
- Gary Gygax (August 1983). Monster Manual II 1st edition. (TSR, Inc), p. 69. ISBN 0-88038-031-4.
- Steven E. Schend, Dale Donovan (September 1998). Empires of the Shining Sea. Edited by Julia Martin. (TSR, Inc.), p. 89. ISBN 0-7869-1237-5.
- Ed Greenwood, Eric L. Boyd (1996). Volo's Guide to All Things Magical. (TSR, Inc), p. 110. ISBN 0-7869-0446-1.
- Steven E. Schend, Dale Donovan (September 1998). Empires of the Shining Sea. Edited by Julia Martin. (TSR, Inc.), p. 38. ISBN 0-7869-1237-5.
- Ed Greenwood and Sean K. Reynolds (May 1999). “Wyrms of the North: Voaraghamanthar, "the Black Death"”. In Dave Gross ed. Dragon #258 (TSR, Inc.).
- Sean K. Reynolds (2002-05-04). Deity Do's and Don'ts (Zipped PDF). Web Enhancement for Faiths and Pantheons. Wizards of the Coast. p. 11. Archived from the original on 2016-11-01. Retrieved on 2018-09-08.