Multiattack

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

Bite

Melee Weapon Attack: +17 to hit, reach 15 ft., one target. Hit: 31 (4d10 + 9) piercing damage plus 9 (2d8) lightning damage.

Claw

Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 22 (3d8 + 9) slashing damage.

Tail

Melee Weapon Attack: +17 to hit, reach 20 ft., one target. Hit: 22 (3d8 + 9) bludgeoning damage and the dragon pushes the target 10 feet away.

Arc Lightning

The dragon targets a creature within 60 feet forcing it to make a DC 24 Dexterity saving throw. The creature takes 22 (4d10) lightning damage on a failure or half damage on a success. Also on a failure the lightning jumps. Choose a creature within 30 feet of the target that hasnt been hit by this ability on this turn and repeat the effect against it possibly causing the lightning to jump again.

Lightning Breath (Recharge 5-6)

The dragon exhales a 120-foot-long 10-foot-wide line of lightning. Each creature in that area makes a DC 24 Dexterity saving throw taking 94 (17d10) lightning damage on a failed save or half damage on a success. A creature that fails the save can't take reactions until the end of its next turn.

Quake

While touching natural ground the dragon sends pulses of thunder rippling through it. Creatures within 30 feet make a DC 24 Strength saving throw taking 22 (4d10) bludgeoning damage and falling prone on a failure. If a Large or smaller creature that fails the save is standing on sand it also sinks partially becoming restrained as well. A creature restrained in this way can spend half its movement to escape.