Aspect of Zellorrasquia - Mother of Tarrasques

Legendary Resistance (5/Day). If Zellorrasquia fails a saving throw, it can choose to succeed instead.

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

Reflective Carapace. Any time Zellorrasquia is targeted by a line spell, or a spell that requires a ranged attack roll, roll a d6. On a 1 to 4, Zellorrasquia is unaffected. On a 5 or 6, Zellorrasquia is unaffected, and the effect is reflected back at the caster as though it originated from Zellorrasquia, turning the caster into the target.

Siege Monster.  Zellorrasquia deals double damage to objects and structures.

Regeneration.  Zellorrasquia regains 31( 2d20+10) HP at the start of her turn.

Reactive. Zellorrasquia can use her reaction twice per round.

Force of Nature. If the aspect would be reduced to 0 hit points, her current hit point total instead resets to 820 hit points, and all creatures immune to her Frightful Presence are no longer immune and she regains any expended uses of Legendary Resistance. All creatures within 30ft of her and on the ground must succeed on a DC 18 Strength saving throw or be knocked prone. Additionally, the aspect can now use the options in the "Mythic Actions" section for 1 hour.

Multiattack. Zellorrasquia can use her Frightful Presence or Spell Twisting Aura. She then makes five attacks: one with her bite, two with her claws, one with her horns, and one with her tail. She can use its Swallow instead of its bite.

Bite. Melee Weapon Attack: +19 to hit, reach 10 ft., one target. Hit: 43 (5d12 + 10) piercing damage. If the target is a creature, it is grappled (escape DC 20). Until this grapple ends, the target is restrained, and the tarrasque can’t bite another target.

Claw. Melee Weapon Attack: +19 to hit, reach 15ft., one target. Hit: 32 (5d8 + 10) slashing damage.

Horns. Melee Weapon Attack: +19 to hit, reach 10ft., one target. Hit: 38 (5d10 + 10) piercing damage.

Tail. Melee Weapon Attack: +19 to hit, reach 20ft., one target. Hit: 26 (5d6 + 10) bludgeoning damage. If the target is a creature, it must succeed on a DC 20 Strength saving throw or be knocked prone.

Frightful Presence. Each creature of Zellorrasquia's choice within 120 feet of it and aware of it must succeed on a DC 18 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 Zellorrasquia 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 Zellorrasquia's Frightful Presence for the next hour.

Spell Twisting Aura. Each creature of Zellorrasquia's choice within 60ft of it that can cast spells must succeed on a DC 18 Charisma saving throw or roll on the Wild Magic table the next time they cast a spell. If the Effect rolled on the table requires a saving throw use the casters Spell Save DC. If the caster is not a Sorcerer and the effect rolled is a 99-100, they instead regain a number of spell slots with a combined level equal to their Proficiency Bonus.

Swallow. The tarrasque makes one bite attack against a Large or smaller creature it is 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 the tarrasque, and it takes 70 (20d6) acid damage at the start of each of the tarrasque’s turns.

If Zellorrasquia takes 80 damage or more on a single turn from a creature inside it, the Aspect must succeed on a DC 20 Constitution saving throw at the end of that turn or regurgitate all swallowed creatures, which fall prone in a space within 10 feet of Zellorrasquia. If the Aspect dies, a swallowed creature is no longer restrained by it and can escape from the corpse by using 30 feet of movement, exiting prone.

Harden Carapace. When Zellorrasquia is targeted with an Attack that would hit, she can increase her AC by 5 until the start of her next turn.

Thickened Hide. When Zellorrasquia takes damage she can half the damage she would take. 

Zellorrasquia 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. Zellorrasquia regains spent legendary actions at the start of its turn.

Attack. Zellorrasquia makes one claw attack or tail attack.

Move. Zellorrasquia moves up to half its speed.

Rampage (Costs 2 Actions). Zellorrasquia moves up to its speed and makes a horn attack with advantage.

Massive Regeneration (Costs 3 Actions). Zellorrasquia regains 73 ( 6d20+10) hit points.

If Zellorrasquia's Force of Nature trait is activated in the last hour, she can use the following options as legendary actions.

Growth. Zellorrasquia grows 10ft in all directions and her reach for her attacks increases by 10ft. She can also make one claw, horn, or tail attack. She remains enlarged until the end of her next turn.

Destructive Rend (Costs 3 Actions). Zellorrasquia immediately takes the Multiattack action. Each attack deals an additional 25 ( 10d4 ) force damage.