Traits

Immovable Shell. The tortoise has advantage on checks and saving throws made to resist being knocked prone or moved against its will.

Amphibious. The tortoise can breathe air and water.

Actions

Multiattack. The tortoise makes one Bite and one Tail Sweep.

Bite. Melee Weapon Attack: +11 to hit, reach 10 ft., one target. Hit: 23 (3d10 + 7) piercing damage.

Tail Sweep. Melee Weapon Attack: +11 to hit, reach 15 ft., one target. Hit: 20 (3d8 + 7) bludgeoning damage. The target must succeed on a DC 19 Strength saving throw or fall prone.

Winter Tide (Recharge 5–6). Each other creature in a 30-foot cone makes a DC 18 Constitution saving throw, taking 45 (10d8) cold damage on a failure or half on a success. On a failure, its speed is reduced by 10 feet until the end of its next turn.

Reactions

Sheltering Shell. When a creature within 10 feet takes damage, the tortoise can reduce that damage by 15.