Undead Fortitude. If damage reduces the zombie to 0 hit points, it must make a Constitution saving throw with a DC of 5 + the damage taken, unless the damage is radiant or from a critical hit. On a success, the zombie drops to 1 hit point instead.

Multiattack. The dragon turtle makes three attacks: one with its bite and two with its claws. It can make one tail attack in place of its two claw attacks.

Bite. Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 26 (3d12 + 7) piercing damage.

Claw. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 16 (2d8 + 7) slashing damage.

Tail. Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 26 (3d12 + 7) bludgeoning damage. If the target is a creature, it must succeed on a DC 20 Strength saving throw or be pushed up to 10 feet away from the dragon turtle and knocked prone.

Freezing Breath (Recharge 5–6). The dragon turtle exhales frozen air in a 60-foot cone. Each creature in that area must make a DC 18 Constitution saving throw, taking 52 (15d6) cold damage on a failed save, or half as much damage on a successful one.

Spew Zombies (1/Day). The zombie dragon turtle disgorges 3d4 normal zombies, which appear in an unoccupied space within 15 feet of it. The disgorged zombies act on their own initiative count. If the zombie dragon turtle has not used this attack when it dies, 3d4 normal zombies erupt from its corpse at the start of its next turn. These zombies act on their own initiative count.