Huge construct, unaligned

Armor Class 16 (natural armor)
Hit Points 95 (10d12 + 30)
Speed 30 ft., swim 30 ft.

19 (+4) 14 (+2) 16 (+3) 1 (-5) 10 (+0) 3 (-4)

Skills Perception +3, Stealth +5
Damage Immunities poison, psychic; bludgeoning, piercing, and slashing from nonmagical weapons not made of adamantine
Condition Immunities charmed, exhaustion, frightened, paralyzed, petrified, poisoned
Senses blindsight 60 ft. (blind beyond this radius), passive Perception 13
Challenge 8 (3,900 XP)

Special Traits

  • Antimagic Susceptibility. The dam-thing is incapacitated while in the area of an antimagic field. If targeted by dispel magic, the dam-thing must succeed on a Constitution saving throw against the caster’s spell save DC or fall unconscious for 1 minute.
  • False Appearance. While it remains motionless, the dam-thing is indistinguishable from what it is built to resemble, a dam that holds back a small amount of water.
  • Immutable Form. The dam-thing is immune to any spell or effect that would alter its form.
  • Sleep Vulnerability. Built into the construct is a susceptibility to the sleep spell. If the dam-thing is subjected to the effects of a sleep spell, it is automatically affected by the spell, regardless of the amount of hit points the dam-thing still has.


  • Bite. Melee Weapon Attack: +7 to hit, reach 10 ft., one creature. Hit: 18 (4d6 + 4) piercing damage. If the attack hits, the dam-thing can use a bonus action to Constrict the target.
  • Constrict. Melee Weapon Attack: +7 to hit, reach 5 ft., one creature. Hit: 22 (4d8 + 4) bludgeoning damage, and the target is grappled (escape DC16). Until this grapple ends, the creature is restrained, and the construct can’t constrict another target.
Section 15: Copyright Notice

Rappan Athuk © 2018, Frog God Games, LLC; Authors Bill Webb, Clark Peterson, Skeeter Green, Tom Knauss, Lance Hawvermale, WDB Kenower, Casey Christofferson, and Greg Raglund; based on the original creation of Bill Webb.