Armor Class 18 (natural armor)
Hit Points 247
Speed 50 ft., burrow 30 ft.
Senses —
Languages —
Challenge 15
Tunneler. The worm can burrow through solid rock at half its burrow speed and leaves a 10-foot-diameter tunnel in its wake.
Multiattack. The worm makes two attacks:
Bite. Melee Weapon Attack: +14 to hit, one target. Hit: 22 (3d8) piercing damage. Target must make a DC 19 Dexterity save, or be swallowed by the worm!
Tail Stinger. Melee Weapon Attack: +14 to hit, one creature. Hit: 19 (3d6 + 9) piercing damage Target must make a DC 19 Constitution save, or take 42 (12d6) poison damage.
AWM, p. 33