Amphibious. The Rimesnake can breathe air and water.

Siege Monster. The Rimesnake deals double damage to objects and structures.

Multiattack. The Rimesnake makes two attacks: one with its bite and one with it's tail.

Bite. Melee Weapon Attack: +10 to hit, reach 10 ft., one target. Hit: 25 (3d12 + 6) piercing damage.

Tail. Melee Weapon Attack: +10 to hit, reach 15 ft., one target. Hit: 25 (3d12 + 6) bludgeoning damage. If the target is a creature, it must succeed on a DC 17 Strength saving throw or be pushed up to 10 feet away from the dragon turtle and knocked prone.

Frost Breath (Recharge 5–6). The dragon turtle exhales freezing mist in a 60-foot cone. Each creature in that area must make a DC 18 Constitution saving throw, taking 42 (12d6) cold damage on a failed save, or half as much damage on a successful one.