Carnivorous Worm

Big Worm. Thats one damn big worm.

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

Echolocator. The worm has advantage on all perception and investigation checks that involve noise.

Bite. Melee Weapon Attack: +4 to hit, reach 15 ft., one target. Hit: 7 (1d10 + 2) piercing damage plus 5 (1d10) poison damage, and the target is grappled (escape DC 13). Until this grapple ends, the target is restrained, and the worm can't bite another target.

Swallow. The worm makes one bite attack against a Medium or smaller target it is grappling. If the attack hits, the target is swallowed, and the grapple ends. The swallowed target is blinded and restrained, it has total cover against attacks and other effects outside the worm, and it takes 10 (3d6) acid damage at the start of each of the worm's turns. The worm can have two targets swallowed at a time. If the worm dies, a swallowed creature is no longer restrained by it and can escape from the corpse using 10 feet of movement, exiting prone.

Acid Spray (Recharge 5–6). The worm sprays acid in a 15-foot cone. Each creature in that area must make a DC 14 Dexterity saving throw, taking 22 (4d10) acid damage on a failed save, or half as much damage on a successful one.

Dive. the worm dives underground but the latter half of it remains partially exposed and vulnerable to attacks until the start of its next turn. Once fully submerged it can stealth attack from underground and Bite or Swallow from below. to hit the target they must fail a Dexterity saving throw (17), the target has advantage on this saving throw if they succeed a Perception check (12).