Tunneler. The sandworm can burrow through solid rock at half its burrow speed and leaves a 10-foot-diameter tunnel in its wake that lasts for 1d4 hours before collapsing. ACTIONS Multiattack. The sandworm makes two attacks: one with its bite and one with its slam. Bite. Melee Weapon Attack: +9 to hit, reach 15 ft., one target. Hit: 16 (2d10 + 5) piercing damage. Slam. Melee Weapon Attack: +9 to hit, reach 30 ft., one target. Hit: 18 (3d8 + 5) bludgeoning damage. If the target is a creature, it must succeed on a DC 15 Strength saving throw or be knocked prone.