Nurglings

Nurglings are what happens when corruption is distilled to its most cheerful. Budded from the ripest filth of the Garden (and, it is whispered, from the innards of far greater daemons), they boil across the realms in giggling tides, each one a fist-sized parcel of bites, poxes, and tremendous enthusiasm. Individually they are almost harmless. Nurglings are never individual.

The legions adore them. Nurglings nest in Blightking blubber, roost in bell-towers, stow away in siege engines, and erupt from wells at the worst possible moment, and no host of Nurgle marches without a carpet of them underfoot. Enemies who laugh at the sight tend to stop once the tide reaches their knees and keeps climbing.