Charged. If the Zapasaurus takes 20 Lightning damage in a single turn it recharges its "Discharge"

Multiattack. The tyrannosaurus makes one Bite attack and two Tail attacks.

Bite. Melee Attack Roll: +11, reach 10 ft. Hit: 33 (4d12 + 7) Piercing damage plus Hit: 10 (3d6) Lightning damage . If the target is a Large or smaller creature, it has the Grappled condition (escape DC 17). While Grappled, the target has the Restrained condition and can’t be targeted by the tyrannosaurus’s Tail. The Target takes 3 (1d6) Lightning damage at the start of its turn while Restrained.

Tail. Melee Attack Roll: +11, reach 15 ft. Hit: 25 (4d8 + 7) Bludgeoning damage. If the target is a Huge or smaller creature, it has the Prone condition.

Discharge (Once Per Day). Ranged Spell Attack: The Zapasaurus shoots a 5ft wide and 100ft long bolt of lightning. Each creature in this bolt must make a Dexterity 16 saving throw. failure take 28 (8d6) Lightning Damage. Success Take half damage.

Lightning Speed. The Zapasaurus is able to Dash as a Bonus Action.