Titanic Dragon Turtle

Amphibious. The dragon turtle can breathe air and water.

Legendary Resistance (1/Day). If the dragon turtle fails a saving throw, it can choose to succeed instead. When it does so, the faint glow cast by its shell winks out. When the dragon turtle uses Retract, it gains one more use of this ability and its shell regains its luminescence.

Innate Spellcasting. The dragon turtles spellcasting ability is Wisdom (spell save DC 17). It can innately cast the following spells, requiring no components: 3/day each: control weather, water breathing, zone of truth

Bite. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 52 (7d12 + 7) piercing damage. If the target is a creature it is grappled (escape DC 21). Until this grapple ends the dragon turtle can't bite a different creature and it has advantage on bite attacks against the grappled creature.

Ram. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 46 (6d12 + 7) bludgeoning damage. This attack deals double damage against objects vehicles and constructs.

Tail. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 46 (6d12 + 7) bludgeoning damage. If the target is a creature it makes a DC 21 Strength saving throw. On a failure it is pushed 15 feet away from the dragon turtle and knocked prone.

Steam Breath (Recharge 5-6). The dragon turtle exhales steam in a 90-foot cone. Each creature in the area makes a DC 20 Constitution saving throw taking 52 (15d6) fire damage on a failed save or half as much on a successful one.

Lightning Storm (1/Day). Hundreds of arcs of lightning crackle from the dragon turtle. Each creature within 90 feet makes a DC 17 Dexterity saving throw taking 35 (10d6) lightning damage on a failure or half damage on a success.

Claws. Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 25 (4d8 + 7) slashing damage.

Retract. When the dragon turtle takes 50 damage or more from a single attack or spell, it retracts its head and limbs into its shell. It immediately regains 20 hit points. While retracted, it is blinded; its Speed is 0; it can't take reactions; it has advantage on saving throws; attacks against it have disadvantage; and it has resistance to all damage. The dragon turtle stays retracted until the beginning of its next turn.

Tail. When the dragon turtle is hit by an opportunity attack, it makes a tail attack.

The dragon turtle can take 3 legendary actions. Only one legendary action can be used at a time and only at the end of another creatures turn. It regains spent legendary actions at the start of its turn.

Claw Kick. The dragon turtle makes a claws attack and then moves up to half its speed without provoking opportunity attacks.

Emerald Radiance (1/Day). Searing green light emanates from the dragon turtle. Each creature within 90 feet makes a DC 17 Dexterity saving throw, taking 70 (20d6) radiant damage on a failure or half damage on a success. A creature that fails the saving throw is blinded until the end of its next turn.

Lightning Storm (1/Day. The dragon turtle recharges and uses Lightning Storm.

Tail (Costs 2 Actions). The dragon turtle makes a tail attack.