A Plague Sprayer is the primary weapon of the abominable Plague Marines of the Death Guard Traitor Legion known as Foul Blightspawn. These cruel and malignant warriors take sick pleasure in watching their victims suffer in the grip of Nurgle's plagues.
On the field of battle, these foul servants of the Plague God spread putrescence and disease with their Plague Sprayers, which unleash a stream of stinking, infectious slime that is so potent that it can melt armour and flesh alike, rotting the souls of their unfortunate victims from within.
The Plague Sprayer is attached to a contraption called the malignant churn, which the Blightspawn uses to mix and prepare his foul brew, stored in an "incubatum" worn on his back.
- Codex Heretic Astartes - Death Guard (8th Edition), pp. 23, 33-34, 62, 78