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Shambling Mound

• Size: Large
• Type: Plant
• Alignment: Unaligned
• AC: 15
• Initiative: -1 (9)
• HP: 110(13d10+39)
• Speed: 30 ft, Swim 20 ft.

ATTR	VAL	MOD	SAVE
STR	18	+4	+4
DEX	8	-1	-1
CON	16	+3	+3
INT	5	-3	-3
WIS	10	+0	+0
CHA	5	-3	-3

• Skills: Stealth +3
• Resistances: Cold, Fire
• Immunities: Lightning; Deafened, Exhaustion
• Senses: Blindsight 60 ft.; Passive Perception 10
• Languages: None
• CR: 5 (XP 1,800; PB +3)

Traits

Lightning Absorption. Whenever the shambling mound is subjected to Lightning damage, it regains a number of Hit Points equal to the Lightning damage dealt.

Actions

Multiattack. The shambling mound makes three Charged Tendril attacks. It can replace one attack with a use of Engulf.

Charged Tendril. Melee Attack Roll: +7, reach 10 ft. Hit: 7 (1d6+4) Bludgeoning damage plus 5 (2d4) Lightning damage. If the target is a Medium or smaller creature, the shambling mound pulls the target 5 feet straight toward itself.

Engulf. Strength Saving Throw: DC 15, one Medium or smaller creature within 5 feet. Failure: The target is pulled into the shambling mound's space and has the Grappled condition (escape DC 14). Until the grapple ends, the target has the Blinded and Restrained conditions, and it takes 10 (3d6) Lightning damage at the start of each of its turns. When the shambling mound moves, the Grappled target moves with it, costing it no extra movement. The shambling mound can have only one creature Grappled by this action at a time.

Lore & Background

Shambling mounds are massive plant creatures formed from rotting vegetation, moss, and decay that have gained sentience through ambient magical energy or druidic influence. These elemental beings of plant matter embody the cycle of death and rebirth that drives natural ecosystems, arising in swamps, marshes, and other wetland environments where organic material accumulates in abundance.

These creatures serve as guardians of wild places, particularly areas where the boundary between life and death becomes blurred in the natural cycle. Shambling mounds possess a primitive intelligence that drives them to protect their territory from perceived threats while maintaining the delicate balance of their wetland homes. They are drawn to areas of electrical activity, which they can absorb and redirect as part of their defensive capabilities.

Combat Tactics

Shambling mounds are resilient combatants that rely on their natural armor, regenerative abilities, and environmental advantages. They prefer to fight in their native swampland, where difficult terrain hampers enemies while providing the mound with concealment and tactical options. Their ability to absorb lightning makes them particularly dangerous against spellcasters who rely on electrical magic.

In battle, shambling mounds use their massive size and strength to grapple multiple opponents, attempting to engulf smaller creatures within their mass. They coordinate with other plant life and swamp creatures, using their connection to the natural world to gain tactical intelligence and environmental support during conflicts.

Encounter Ideas

1. The Awakened Swamp Environmental destruction has awakened an ancient shambling mound that now terrorizes travelers through its swampland domain. The party must either find a way to appease the creature or discover what disturbance caused its violent awakening.

2. The Lightning Harvester A shambling mound has taken residence near a settlement, drawn by their use of electrical magic or technology. The creature's presence disrupts the community's activities while it feeds on their electrical sources, requiring delicate negotiations or relocation efforts.

3. The Decomposer's Garden Deep in a marsh, a shambling mound tends a grove of unusual plants that grow only in soil enriched by its presence. The party seeks rare botanical specimens from this garden but must convince the protective guardian to allow access to its treasured plants.

4. The Plague Bearer A diseased shambling mound spreads a supernatural plague through the wetlands, threatening to destroy the ecosystem it once protected. The party must find a cure for the creature's affliction while avoiding becoming infected themselves.

Environmental Effects

• Difficult Terrain: The shambling mound's presence makes surrounding swampland even more treacherous and hard to navigate
• Electrical Absorption: Lightning strikes in the area are drawn to the creature, making electrical storms particularly dangerous for nearby creatures
• Plant Growth: The mound's influence causes accelerated plant growth, creating dense vegetation that provides cover but blocks movement
• Decomposition Acceleration: Organic matter breaks down rapidly near the creature, enriching soil but creating hazardous gases

Treasure

• Swamp Gas Pearls (300-1200 gp): Rare crystalline formations created by compressed marsh gases within the creature's body
• Lightning Wood (500-1500 gp): Specially charged wood that retains electrical properties for crafting magical items
• Bog Iron (200-800 gp): Iron deposits concentrated by the mound's presence, valuable for weapon crafting
• Preserved Specimens (varies): Plants and creatures perfectly preserved within the mound's acidic interior
• Electrical Essence (1000-3000 gp): Concentrated electrical energy stored within crystalline nodules in the creature's core

Plot Hooks

1. The Missing Druid A druid investigating environmental changes in a swamp has disappeared, with their last known location being a shambling mound's territory. The party must determine whether the druid became the creature's victim or underwent some form of transformation.

2. The Electric Storm Unusual electrical storms plague a region, all seeming to center around a massive shambling mound that has grown to enormous size. Investigation reveals the creature is somehow connected to planar electrical phenomena that threaten regional stability.

3. The Symbiotic Relationship A shambling mound and a human settlement have developed an unusual partnership, with the creature providing protection in exchange for organic waste and electrical energy. When this relationship breaks down, both sides seek mediators to restore their beneficial arrangement.

4. The Ancient Guardian Legends speak of a shambling mound that guards the entrance to a lost druid circle's sacred site. The party must prove their worthiness to the ancient guardian or find alternative ways to access the hidden location without disturbing the natural balance.