The Mawcannon is a terrible Warp-based energy weapon that is used by Soul Grinders, Plague Hulks, and Blight Drone Daemon Engines. Mawcannon is the name given to the Plague Hulk and Soul Grinder's natural ability to unleash different types of lethal Warp energies through their mouths. The weapon-mouth of a Soul Grinder can vomit forth a torrent of burning Warpfire known as a Baleful Torrent which is capable of engulfing entire structures in blazing ethereal energy. The Soul Grinder's Mawcannon can also spit out huge roiling masses of mutating phlegm at incredible distances, destroying entire enemy squads in one great blast. It can continue this form of attack throughout its time on the battlefield, which is known as a Phlegm Bombardment. There are some Soul Grinders that are capable of using their Mawcannon to fire their whip-like tongues like searing energy rays. All Chaos Soul Grinders are capable of using the Mawcannon in conjunction with their other weapons, such as the Iron Claw and Harvester Cannon. The Plague Hulk is capable of vomiting forth a tide of unspeakable foulness so potent that it can rot flesh and corrode even the strongest of metal.
The Mawcannon used by Blight Drone Daemon Engines is smaller and takes the form of an actual weapon rather than a natural ability of the construct. The Blight Drone's Mawcannon is located on the front of the creature, just above its Reaper Autocannon. The Mawcannon of the Blight Drone differs from the Soul Grinder's in several ways, first of which is that it is smaller and less powerful. As a Daemon Engine of Nurgle, the Blight Drone's Mawcannon fires out gouts of corrosive toxic bile that is powerful enough to eat through metal and liquify flesh in seconds as opposed to the Soul Grinder's radiant Warpfire. The Blight Drone's phlegm attack is similar to that of the Soul Grinder, yet is smaller in area of effect and deals less damage to its targets.
- Codex: Chaos Daemons (4th Edition), pp. 17, 44-45
- Codex: Chaos Daemons (6th Edition), pp. 60, 102
- Imperial Armour Volume Seven - The Siege of Vraks - Part Three, pp. 151-153
- Imperial Armour Apocalypse II, pp. 65, 72
- Imperial Armour Modelling Masterclass II, pp. 78-79