The Betcher's Gland, also known as the Poison Bite, is the 17th of the 19 genetically-engineered gene-seed organs that are implanted into a Space Marine Neophyte to produce a new Astartes. Consisting of two glands that are implanted into multiple locations inside a Space Marine's mouth, including the inside of the lower lip, in the salivary glands or in the hard palate, these two glands working in tandem transform an Astartes' saliva into a corrosive, blinding acid when consciously triggered.

This allows a Space Marine to spit a wad of corrosive acid with the effect of blinding, wounding or even killing an enemy outright. These implants' more common use is to aid in the digestion of unusually difficult or impossible things to digest, such as cellulose. In the gene-seed of several Primarchs, like that of Rogal Dorn, this organ has atrophied and is no longer as effective or has simply ceased to function entirely in the Astartes of the Chapters that use those Primarchs' gene-seed.

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