Pack Tactics. The kruthik has advantage on an attack roll against a creature if at least one of the kruthik's allies is within 5 feet of the creature and the ally isn't incapacitated.

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

Multiattack. The kruthik makes two Stab or Spike attacks.

Stab. Melee Weapon Attack: +7 to hit, reach 10 ft., one target. Hit:9 (1d10 + 4) piercing damage.

Spike. Ranged Weapon Attack: +6 to hit, range 30/120 ft., one target. Hit:7 (1d6 + 4) piercing damage.

Acid Spray (Recharge 5–6). The kruthik 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.