Bore Worm

Gargantuan Construct, Unaligned

AC: 18

Initiative: -2 (8)

HP: 247 (15d20 + 90)

Speed: 50 ft., burrow 30 ft.

STR: 28 (+9)
DEX: 7 (-2)
CON: 22 (+6)
INT: 1 (-5)
WIS: 8 (-1)
CHA: 4 (-3)

Saving Throws: Con +11, Wis +4

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

CR: 16 (XP 15,000; PB +5)

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.

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Source: Waterdeep: Dungeon of the Mad Mage, p. 171 - Licenses and attribution