Bore Worm

Gargantuan Construct, Unaligned

Armor Class 18 (natural armor)

Hit Points 247 (15d20 + 90)

Speed 50 ft., burrow 30 ft.

STR

DEX

-2

CON

INT

-5

WIS

-1

CHA

-3

Saving Throws CON +11, WIS +4

Damage Immunities poison, psychic; bludgeoning, piercing, slashing, from nonmagical attacks that aren't adamantine

Condition Immunities Blinded, Charmed, Deafened, Exhaustion, Frightened, Paralyzed, Petrified, Poisoned, Prone

Senses blindsight 30 ft., tremorsense 60 ft., passive Perception 9

Languages —

Challenge 16 (15,000 XP)

Traits

Tunneler. The worm can burrow through solid rock at half its burrow speed and leaves a 10-foot-diameter tunnel in its wake.

Regeneration. The worm regains 10 hit points at the start of each of its turns if it has at least 1 hit point.

Actions

Multiattack. The worm makes two attacks: one with its grinding jaws and one with its stinger.

Grinding Jaws. Melee Weapon Attack: +9 to hit, reach 10 ft., one target. Hit:22 (3d8 + 9) slashing damage.

Tail Stinger. Melee Weapon Attack: +14 to hit, reach 10 ft., one creature. Hit:19 (3d6 + 9) piercing damage, and the target must make a DC 19 Constitution saving throw, taking 42 (12d6) poison damage on a failed save, or half as much damage on a successful one.

Lore

Trobriand modeled this 100-foot-long, 15-foot-diameter drilling machine after a purple worm. Unless Trobriand commands it to do otherwise, the worm tirelessly moves through well-worn tunnels and trenches. It mindlessly attacks anything that gets in its way, and occasionally ventures up to level 12 or down to level 14. Characters hear it long before they see it.