Warhammer Age of Sigmar. Maggotkin of Nurgle. Nurglings

Nurglings are tiny,
mischievous daemons, resembling a miniature version of the Chaos God
Nurgle. Nurglings rarely reach 1 foot in height, much smaller than the
Plaguebearer or Great Unclean One.

On the battlefield Nurglings will normally gather in monstrous swarms.
There favorite method of attack is to overrun a single individual and
bring him down under the sheer mass of bodies.