Magic Resistance: Zane has advantage against magical effects from spells.

Reflective Hide: All ranged weapon attacks that deal piercing damage are reflected back at the creature.

Siege Monster: Zane does triple damage to structures.

Gargantuan Tremors: If Zane is moving on the ground, then the ground within a 400-foot radius of him is difficult terrain.

Legendary Resistance (3/day): If Zane fails a saving throw, he can choose to succeed instead.

Innate Spellcasting. Zane's innate spellcasting allows him to cast these spells (Save DC 20, +14 spell attacks):
At will: Detect Magic, Dispel Magic, and Faerie Fire.
3/day: Antimagic Field, Blade Barrier, and Earthquake.

Multiattack: Zane can use his Frightful Presence. He then makes 5 attacks: one with his bite, 3 with his claws, and 1 with his tail.  He can use his Swallow instead of his bite.

Bite: Melee Weapon Attack: +20 to hit, reach 25 ft., one target. Hit: 32 (4d10 + 12) piercing damage plus 22 (5d8) acid damage

Claw: Melee Weapon Attack: +20 to hit, range 25 ft., one target. Hit: 27 (5d6 + 10) slashing damage.

Tail: Melee Weapon Attack: +20 to hit, range 30 ft., one target.  Hit: 28 (4d8 +10) bludgeoning damage.  If the target is a creature, it must succeed on a DC 25 Strength saving throw or be knocked prone and lose concentration on spells.

Frightful Presence: Each creature of Zane's choice within 300 feet of him and aware of him must succeed on a DC 24 Wisdom saving throw or become frightened for 1 minute. A creature can repeat the saving throw at the end of each of its turns, with disadvantage if Zane is within line of sight, ending the effect on itself on a success. If a creature’s saving throw is successful or the effect ends for it, the creature is immune to Zane’s Frightful Presence for the next 24 hours.

Swallow: Zane makes one bite attack against a Huge or smaller creature he's grappling. If the attack hits, the target takes the bite’s damage, the target is swallowed, and the grapple ends. While swallowed, the creature is blinded and restrained, it has total cover against attacks and other effects outside Zane, and it takes 63 (18d6) acid damage at the start of each of Zane's turns.

If Zane takes 60 damage or more on a single turn from a creature inside it, Zane must succeed on a DC 22 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall prone in a space within 60 feet of Zane. If Zane dies, a swallowed creature is no longer restrained by it and can escape from the corpse by using 60 feet of movement, exiting prone.

Acidic Breath (Recharge 5-6):  Zane exhales acid in a 120-foot cone.  Each creature in the area must make a DC 25 Dexterity saving throw, taking 98 (20d8) acid damage, or half as much damage on a successful save.

Crushing Step:  Zane stomps on the ground, each creature within a 200 ft radius of him must make a DC 20 Dexterity saving throw or be knocked prone.

Agitated Slap: After being hit with a melee weapon attack, Zane swats at the creature that hit him.  The creature must make a DC 25 Strength saving throw or take 14 (4d6) bludgeoning damage and be knocked prone, taking half and avoiding being knocked prone on a successful save.

Zane 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. Zane regains spent legendary actions at the start of his turn.

Bite (Costs 1 Action): Zane makes one bite attack.  He can use his Swallow instead of his bite.

Attack (Costs 1 Action):  Zane makes one claw attack or one tail attack.

Wings (Costs 2 Actions):  Zane makes an attack with his swings.  He moves up to 150 ft into the air and all creatures in a 100 ft cone in front of him must make a DC 22 Dexterity saving throw or be knocked prone and moved up to 60 feet back, avoiding being prone and only moving 30 feet on a successful save.

If Zane's mythic trait is active, he can use the options below as legendary actions for 1 hour after using his Orb of Dragonkind

Crushing Flight (Costs 2 Actions):  Zane lands on the ground, shaking the earth.  Each creature in a 300-foot radius of Zane must make a DC 24 Dexterity saving throw or take 45 (10d8) bludgeoning damage or be knocked prone and lose concentration on spells, avoiding being prone and taking half as much damage on a successful save.

Acidic Flame Breath (Recharge 5-6):  Zane exhales an acidic fire in a 120-foot cone in front of him.  Each creature in the area must make a DC 25 dexterity saving throw or take 72 (16d8) acid damage and 72 (16d8) fire damage, or half as much on a successful save.