Voltragh, the Storm Maw

Magic Resistance. Voltragh has advantage on saving throws against spells and other magical effects.

Static Discharge. Any creature that touches Voltragh or hits it with a melee attack while within 5 feet takes 10 (3d6) lightning damage.

Tremors. Voltragh Rears back on his hind legs and slam back down causing a tremor in a 10 foot circle around him anyone caught inside the circle must pass a DC 14 athletics check or be knocked prone. 

Multiattack. Voltragh makes three attacks: one with its Bite and two with its Claws.

Bite. Melee Weapon Attack: +13 to hit, reach 10 ft., one target. Hit: 24 (3d10 + 7) piercing damage plus 7 (2d6) lightning damage.

Claw. Melee Weapon Attack: +13 to hit, reach 5 ft., one target. Hit: 17 (2d8 + 7) slashing damage.

Lightning Roar (Recharge 5-6). Voltragh emits a thunderous, electrified roar in a 60-foot cone. Each creature in that area must make a DC 20 Constitution saving throw, taking 54 (12d8) lightning damage on a failed save, or half as much on a successful one. A creature that fails this save is also stunned until the end of its next turn.

Voltragh can take 3 legendary actions, choosing from the options below. Only one legendary action option can be used at a time and only at the end of another creature's turn. Voltragh regains spent legendary actions at the start of its turn.

Detect.Voltragh makes a Wisdom (Perception) check.

Claw Attack. Voltragh makes a claw attack.

Electrifying Leap (Costs 2 Actions). Voltragh leaps up to 30 feet to a space it can see. Each creature within 10 feet of the landing point must succeed on a DC 20 Dexterity saving throw or take 21 (6d6) lightning damage and be knocked prone.