Bone Worm
Large Monstrosity
- Armor Class 15 (Natural Armor)
- Hit Points 170 (20d10+60)
- Speed 30ft., burrow 50ft.
STR DEX CON INT WIS CHA 19 (+4) 13 (+1) 16 (+3) 4 (-3) 10 (+0) 7 (-2)
- Saving Throws Str +7, Con +6
- Skills Athletics +7, Perception +3
- Damage Vulnerabilities fire
- Damage Resistances bludgeoning, piercing, and slashing from nonmagical attacks
- Condition Immunities prone
- Senses blindsight 30ft. (blind beyond this radius), tremorsense 60ft., passive Perception 13
- Languages -
- Challenge 5 (1,800 XP)
Acidic Coating. The Bone Worm can melt stone with the acidic outer layer of slime secreted from its body. Any creature that comes into contact with the creature takes 3 (1d6) acid damage.
Tunneler. The Bone Worm can burrow through solid rock at half its burrow speed and leaves a 10-foot-diameter tunnel in its wake.
Thrash. When the Bone Worm is reduced to half health, it begins to thrash wildly. All creatures within 15ft of the Bone Worm must make a Dexterity saving throw (DC 15) or take 26 (4d12) bludgeoning damage and be knocked prone. On a successful save, a creature takes half damage and is not knocked prone.
Actions
Multiattack. The Bone Worm makes three attacks.
Slam Melee Weapon Attack: +7 to hit, reach 5ft., one target. Hit 13 (2d8 + 4) bludgeoning damage + 3 (1d6) acid damage.
Constrict Melee Weapon Attack: +7 to hit, reach 5ft., one creature. Hit: 13 (2d8 + 4) bludgeoning damage + 3 (1d6) acid damage, and the target is grappled (escape DC 15). Until this grapple ends, the creature is restrained, and the Bone Worm can't constrict another target. At the beginning of each of the constricted creature's turns, it takes 3 (1d6) acid damage.
Squeeze Melee Weapon Attack: While the Bone Worm has a creature grapple, it can make a squeeze attack on that creature. +7 to hit, reach 5 ft., one target. Hit: 9 (1d10 + 4) bludgeoning damage +7 (2d6) acid damage.
Reactions
Squirm. When a creature successfully attacks the Bone Worm with a weapon attack, it can use its reaction to squirm, flinging acid on the creatures around it. Every creature within 5ft. of the Bone Worm must make a Dexterity saving throw or take 3 (1d6) acid damage on a failure and none on a success.