Amphibious. The dragon can breathe air and water.

Multiattack. The dragon makes three attacks: one with its bite and two with its claws.

Bite. Melee Weapon Attack: +12 to hit, reach 10 ft., one target. Hit: 18 (2d10 + 7) piercing damage.

Claw. Melee Weapon Attack: +12 to hit, reach 5 ft., one target. Hit: 14 (2d6 + 7) slashing damage.

Tail. Melee Weapon Attack: +12 to hit, reach 15 ft., one target. Hit: 16 (2d8 + 7) bludgeoning damage.

Breath Weapons (Recharge 5–6). The dragon uses one of the following breath weapons.

Lightning Breath. The dragon exhales lightning in a 90- foot line that is 5 feet wide. Each creature in that line must make a DC 19 Dexterity saving throw, taking 66 (12d10) lightning damage on a failed save, or half as much damage on a successful one.

Repulsion Breath. The dragon exhales repulsion energy in a 30-foot cone. Each creature in that area must succeed on a DC 19 Strength saving throw. On a failed save, the creature is pushed 60 feet away from the dragon.

Change Shape. The dragon magically transforms into any creature that is Medium or Small, while retaining its game statistics (other than its size). This transformation ends if the dragon is reduced to 0 hit points or uses a bonus action to end it.

The dragon can take a number of legendary actions equal to the number of players. At the end of a player’s turn that player can choose to have the dragon use one of its legendary actions choosing from the options below, only one legendary action option can be used at a time. The dragon regains spent legendary actions at the start of its turn.

Bite. The dragon makes one Bite attack.

Claw. The dragon makes one Claw attack.

Tail. The dragon makes one Tail attack.

Move. The dragon moves up to its speed without provoking opportunity attacks.

Frighten Foe. The dragon targets one creature it can see within 30 feet of it. If the target can see or hear it, the target must succeed on a DC 17 Wisdom saving throw or be frightened of the dragon until the end of dragon’s next turn.