Keen Hearing and Smell. The Zinogre has advantage on Wisdom (Perception) checks that rely on hearing or smell. 

Pounce. If the Zinogre moves at least 20 feet straight toward a creature and then hits it with a claw attack on the same turn, that target must succeed on a DC 19 Strength saving throw or be knocked prone. If the target is prone, the Zinogre can make one bite attack against it as a bonus action.

Static Charge. The Zinogre is able to build up a charge on it's body, when it is charged each of it's melee attacks deal an additional 3d10 lightning damage.

Legendary Resistance (3/Day). If the Zinogre fails a saving throw, it can choose to succeed instead.

Thunderous Howl. The Zinogre let loose a will shattering howl, each creature that is able to hear it must make a WIS saving throw DC 16 or be frightened of it for 1 minute. Any creature frightened this way is able to make it's save again at the end of its turn.

Claw. Melee Weapon Attack: +17 to hit, reach 5 ft., one target. Hit: 22 (3d8 + 10) Slashing damage. 

Bite. Melee Weapon Attack: +17 to hit, reach 10 ft., one target. Hit: 19 (2d10 + 10) Piercing damage plus (2d6) lightning damage.

Tail sweep. Melee Weapon Attack: +17 to hit, reach 15 ft., one target. Hit: 27 (3d12 + 10) Bludgeoning damage.

Opportunity of attack. This creature is able to make a claw attack at any creature that leaves it attack range of it's own free will.

This creature gets three legendary actions to use during any turn (maximum of 3) and they recharge on each of it's turns.

Charge (Costs 2 Actions). The Zinogre Charges it's self with an electric current. This charged state lasts for 3 rounds

Discharge (Costs 3 Actions). The Zinogre discharges it's electric state in a 50ft cube around itself. Each creature within range must make a DEX saving throw of 18 or take 5d12 lightning damage or half as much on a successful save.

Claw swipe (Costs 1 Action). The Zinogre makes a single claw melee attack at a creature within range.

Move (Costs 1 Action). The Zinogre moves up to half its speed.