Multiattack. The horror makes two attacks with its claws.

Claw. Melee Weapon Attack: +6 to hit, reach 5 ft., one target. Hit: 19 (3d10 + 3) slashing damage.

Wave of Bones (Recharge 5–6). The horror crashes into foes like a wave before quickly reforming. Each creature within 10 feet of the horror must make a DC 15 Dexterity saving throw, taking 18 (4d8) bludgeoning damage on a failed save, or half as much damage on a successful one. A creature that fails this saving throw is also knocked prone.