Armor Class 18 (natural armor)
Hit Points 247 (15d20 + 90)
Speed 50 ft., burrow 30 ft.
Saving Throws CON +11, WIS +4
Damage Immunities poison, psychic, [object Object]
Condition Immunities blinded, charmed, deafened, exhaustion, frightened, paralyzed, petrified, poisoned, prone
Senses blindsight 30 ft., tremorsense 60 ft., passive Perception 9
Languages —
Challenge 16
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.
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.
WDMM, p. 171