Cast from black iron the lip of this wide cauldron is ringed with corroded chains and ruddy smeared hooks. Within the vessel bubbles a noisome stew of amber and honey hew; fragmented honeycombs and rotting limbs occasionally crest the surface. Multifaceted eyes stamped into the metal twitch back and forth. When the boil spots a potential victim its eyes fixate on the target, its body lurches, and its hooked chains writhe akin to excited snakes.

Pestilence Engine. A boil's primary function is to spread Harvest Rot wherever the Lord of Fallowfields' covetous gaze falls. Once established the cauldron travels from village to village as a rolling cloud of jaundice gas. Once established a new area the boil targets farms and camps on the fringes first, raising a bumper crop of bubonic drifters before moving on. Once the village, or even city, is under siege from the infectious undead the boil will drift into the slums and begin to putrify the city from within. The boil follows this pattern by rote alone, and will only deviate from it if ordered to perform a different function by a fey of the warning court.

Artiface of Misery. Loathed by his kin and burdened with perpetually rotting resources the Duke of Autumn's End resorts to dastardly deeds to obtain what he desires. Despite his mother's castigation, the archfey secretly seeded the rivers of his uncle's, The Lancer Prince, with Harvest Rot; swiftly leading to an epidemic. While suspicious the Lancer Prince had little choice but to turn to Lord of Fallowfields for help as the devious nephew was well-versed in a myriad of contagions. The Duke offered his uncle a deal, a cure for the plague if a host of infected artisans and their tools would be placed under his care until such time as they were healthy. The Liege of Lightning agreed. Of course, the fiend had no intention of ever curing these poor sods but instead keeps them perpetually suffering on the brink of being hale.

Boil

Large construct, unaligned

Armor Class 15 (natural armor)

Hit Points 45 (6d10 + 12)

Speed 0ft

Str 16 Dex 3 Con 14 Int 5 Wis 10 Cha 5

Damage Immunities lightning, necrotic, poison.

Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned, prone.

Senses darkvision 60ft, passive Perception 10

Languages understands Sylvan but can't speak

Challenge 3 (700 XP)

Engulf.

The boil takes up its entire space. A creature that is engulfed by the boil has total cover and is considered restrained. If a creature begins its turn engulfed by the boil it takes 7 (2d6) fire damage and must make a DC 14 Constitution save or contract Harvest Rot (see below). An engulfed creature may use its action to attempt to escape with either an Athletics (Strength) roll or Escape Artist (Dexterity) roll DC 14. If a creature ends its turn engulfed by the boil it is subject to the drowning rules.

A creature within 5 feet of the boil can take an action to pull a creature or object out of the boil. Doing so requires a successful DC 14 Strength check, and the creature making the attempt takes 7 (2d6) fire damage.

The boil can hold only 1 Large creature or up to 6 Medium or smaller creatures inside at a time. Whenever the boil dies creatures or objects within are spat out into an adjacent square of the cauldron.

Innate Spellcasting.

The boil’s spellcasting ability is Wisdom (spell save DC 10, +2 to hit with spell attacks). It requires no material components to cast its spells.

At will: misty step

Actions

Multiattack.

The boil makes two hooked chain attacks.

Hooked Chain.

Melee Weapon Attack: Melee Weapon Attack: +5 to hit, reach 10 ft., one target. Hit: 10(1d10+4) piercing damage. In addition, the creature is grappled by the hooked chain. A creature may use it’s action to attempt escape with either an Athletics (Strength) roll or Escape Artist (Dexterity) roll DC 13. The hooked can be attacked (AC 15; 5 hit points; immunity to poison, necrotic and lightning damage). Destroying the hooked chain causes no damage to the boil, which can manifest a replacement hooked chain on its next turn. A boil loses one hooked chain attack for each creature it has grappled..

Reel.

As a bonus action the boil may force one creature grappled by the its hooked chain must make a DC 14 Strength saving throw, provided that the target is large or smaller. On a failure, the target is pulled into boil and Engulfed. The creature is then no longer considered grappled by the hooked chain.

Rolling Steam (Recharge 6).

The cauldron emits a cloud of noxious gas. Each creature within 10ft of the boil must succeed a DC 13 Constitution save or take 7 (2d6) necrotic damage and contracts Harvest Rot (see below).

Optional Rule: Harvest Rot. he character has Disadvantage on Dexterity checks and Dexterity saves due to painful buboes covering on their body. Also, any successful attack against the victim deals an additional 2 (1d4) necrotic damage as it also bursts buboes. A creature who dies while infected with Harvest Rot rises the following morning as a Bubonic Drifter. A creature may repeat the Constitution save each day, success ending the disease.