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

Multiattack: the wurm attacks once with its bite, and once with its tail. instead of attacking with his bite, he can attack with his swallow

Bite: 10 ft. +9 to hit 3d6 +6 piercing damage

Tail: 30 ft. +9 to hit 1d12 +6 bludgeoning damage

Swallow: 5 ft. +9 to hit the target is grappled restrained and blinded. at the beggining of the Young Slate Wurm's upkeep, the target takes 3d6 acid damage. if the Young Slate Wurm takes 12 damage in one turn, he falls prone and the target/targets can crawl out.