Multiattack

The dragon attacks with its bite and twice with its claws. In place of its bite it can use Lightning Pulse.

Bite

Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 23 (3d10 + 7) piercing damage plus 4 (1d8) lightning damage.

Claw

Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 20 (3d8 + 7) slashing damage.

Tail

Melee Weapon Attack: +13 to hit, reach 15 ft., one target. Hit: 20 (3d8 + 7) bludgeoning damage and the dragon pushes the target 10 feet away.

Trident (Humanoid Form Only)

Melee or Ranged Weapon Attack: +13 to hit, reach 5 ft. or range 20/60 ft., one target. Hit: 10 (1d6 + 7) piercing damage.

Lightning Pulse

The dragon targets one creature within 60 feet forcing it to make a DC 20 Dexterity saving throw. The creature takes 22 (4d10) lightning damage on a failure or half damage on a success. If the initial target is touching a body of water all other creatures within 20 feet of it and touching the same body of water must also make the saving throw against this 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-long 5-foot-wide line. Each creature in the area makes a DC 20 Dexterity saving throw taking 69 (13d10) lightning damage on a failed save or half damage on a success. A creature that fails the saving throw can't take reactions until the end of its next turn.

Ocean Surge

The dragon exhales a torrent of seawater in a 30-foot cone. Each creature in the area makes a DC 20 Strength saving throw. A creature that fails is pushed 30 feet away from the dragon and knocked prone while one that succeeds is pushed only 15 feet away.

Change Shape

The dragon magically takes the shape of a humanoid or beast or changes back into its true form. It reverts to its true form if it dies. Any equipment it is wearing or carrying is absorbed or borne by the new form (dragons choice). In the new form the dragons stats are unchanged except for its size. It can't use Lightning Pulse Breath Weapons Tail Attack or Wing Attack except in dragon form. In beast form it can attack only with its bite and claws if appropriate to its form. If the beast form is Large or smaller the reach of these attacks is reduced to 5 feet. In humanoid form it can attack only with its trident.