The vibrantly blood-colored, two-inch-long larval stage of a wretched necrophagic insect, the Lily Worm thrives on battlefields and in siege trenches – anywhere its adult form can reach by crawling from the slain host it once fed on before laying its eggs in wait. Once consumed by someone, an egg hatches and makes its way to the brain of the infected, where it rests and feeds. Through a combination of painful gnawing and release of neurotoxins, the Lily Worm changes its host’s brain such that their muscles spasm and falter under the right conditions: peaking adrenaline and stress chemicals, accelerated heart rate, vigorous movementthe exact response to violence.

At first, this manifests as a mere twitch, but with time results in utterly faltering sword hands and bow arms, or in the worst of cases a complete shutdown of the body in a fight. The Worm wants its host slain, that it might emerge among a feast of corpses, gorge itself, and begin the cycle anew. Outbreaks are rare, but if unchecked stand to turn an army of hardened veterans into helpless, jittering cravens.

Removal of the worm is nigh impossible without releasing a fatal dose of its neurotoxins – it can only be sedated with constant treatment until it is forced to (painfully but not fatally) wriggle free of its host and try its luck reproducing without its feast of corpses – an almost always futile endeavor. Infection is primarily spread through consumption of or exposure of eyes and ears to infested water. Once exposed, a humanoid must succeed in a DC 8 Constitution save or become infected.

Goblinoids are notably immune to the parasite. A humanoid so infected must make a Constitution save at the start of any combat and every 10 turns thereafter. If they pass at DC 10, there is no effect. If they fail at DC 10, they have disadvantage on all attack actions.

If they fail at DC 5, they go Unconscious.

The parasite stays indefinitely without treatment or death. A dose of Basic Poison consumed by the host will purge it, as will any stronger poison.