- Abd al-Hazir(src)
Maggot Broods are Beast enemies in Act V of Diablo III. They are only encountered in Blood Marsh, Paths of the Drowned and local caves. One can easily recognize them by a bunch of glowing white and green worms hanging from the beast's body.
In-game
Maggot Broods often hide in the ground, emerging to attack the player. In addition to their melee attack, they can hurl a volley of 5-10 putrid Maggots attached to their backs. Each Maggot is a separate unit (capable of attacking with its jaws), and explodes in a short-ranged blast of Poison damage when killed. In a few seconds, the Maggot Brood is ready for another launch as a new portion of Maggots grows quickly at its body.
Apparently, the Maggots are parasites and not the beast's own progeny: Moggra, the unique Maggot, can be found in the caves, and numerous dead Maggot Broods are scattered throughout the marsh, presumably died from being leeched dry.