Swarms of rot grubs

Rot grubs are finger-sized maggots that feast on living or dead flesh, though they can also survive on plant matter. These vile creatures infest corpses and piles of decaying matter, attacking any living beings that disturb their nests. When they swarm, they become a writhing mass of flesh-eating parasites, capable of overwhelming even the most seasoned adventurers.

A swarm of rot grubs can occupy the same space as another creature, burrowing into their flesh with alarming speed. Once inside, the grubs instinctively chew their way towards the heart, causing excruciating pain and potentially fatal damage. The only way to stop them is to apply fire to the bite wound before they burrow too deep, or to use magic that cures disease.