Swampgas Shade

Medium undead, neutral evil

Armor Class 13
Hit Points 39 (6d8 + 12)
Speed 0 ft., fly 40 ft. (hover)

6 (–2) 17 (+3) 15 (+2) 8 (–1) 12 (+1) 8 (–1)

Saving Throws Wis +3
Skills Stealth +5
Damage Vulnerabilities radiant
Damage Resistances acid, cold, fire, lightning, thunder; bludgeoning, piercing, and slashing from nonmagical attacks
Damage Immunities necrotic, poison
Condition Immunities exhaustion, frightened, grappled, paralyzed, petrified, poisoned, prone, restrained
Senses darkvision 60 ft., passive Perception 10
Languages understands all languages it knew in life but can’t speak
Challenge 2 (450 XP)


  • Amorphous. The swampgas shade can move through a space as narrow as 1 inch wide without squeezing.
  • Rejuvenation. If it dies within its bound region, the swampgas shade returns to life in 1d4 days and regains all its hp. This trait doesn’t function if the swampgas shade is put to rest, which occurs after its corpse has been reburied outside the swamp.
  • Swampbound. The swampgas shade is bound to a region of swamp within 1 mile of its body. If the shade leaves this region, it loses its Soul Drain action until it returns to the region. If it remains outside the region, it automatically teleports back to its corpse after 24 hours, regardless of distance.
  • Swamp Camouflage. The swampgas shade has advantage on Dexterity (Stealth) checks made to hide in swampy terrain.
  • Undead Nature. The swampgas shadow doesn’t require air, food, drink, or sleep.


  • Soul Drain. Melee Weapon Attack: +5 to hit, reach 5 ft., one creature. Hit: 12 (2d8 + 3) psychic damage, and the target’s Charisma score is reduced by 1d4. The target dies if this reduces its Charisma to 0. Otherwise, the reduction lasts until the target finishes a short or long rest. If a Humanoid dies from this attack, it can’t be restored to life until the swampgas shade is put to rest (see the Rejuvenation trait).
  • Haunting Murmurs. Ranged Spell Attack: +3 to hit, range 60 ft., one creature. Hit: 8 (1d8 + 3) psychic damage.


  • Swampland Stealth. The swampgas shade takes the Hide action. It must be in swampy terrain to use this bonus action.


An ethereal shadow of hatred and swampgas haunts the fens, and seeks to duplicate its own tragic demise.

A swampgas shade is the aggrieved soul of a humanoid murdered in a swamp. Mired in muck, the body cannot decompose, and spawns an undead instead. The soul is trapped on the Material Plane, tied to the area within a mile of its corpse. The soul grows furious at its condition as time passes, eventually combining with swampgas to form a ghostly undead that lashes out at others, whispering in the ears of the living.

Restless Slumber. The swampgas shade can be put to rest by finding and properly interring its corpse outside the swamp.

Otherwise, the shade returns to haunt the swamp anew shortly after being slain.

Vile Compact. Dark powers often seek out swampgas shades, promising relief from their eternal torture if they can ensnare souls of those they kill. As it kills others, it traps their souls, which it barters in exchange for its freedom.

Section 15: Copyright Notice

Tome of Beasts 3 © 2022 Open Design LLC; Authors: Eytan Bernstein, Celeste Conowitch, Benjamin L. Eastman, Robert Fairbanks, Scott Gable, Basheer Ghouse, Richard Green, Jeremy Hochhalter, Jeff Lee, Christopher Lockey, Sarah Madsen, Ben Mcfarland, Jonathan Miley, Kelly Pawlik, Sebastian Rombach, Chelsea Steverson, Brian Suskind, Mike Welham

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