Avatar of Extermination

Legendary Action (3/Day). When it is not the Avatar of Extermination, it can chose to make a players turn it's own. This makes the player wait until the end of the Avatar of Exterminations new turn to take their turn. Cannot be used back-to-back.

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

Magic Resistance. The Avatar of Extermination has advantage on saving throws against spells and other magical effects.

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

Siege Monster. The Avatar of Extermination deals double damage to objects and structures.

Multiattack. The Avatar of Extermination can use its Frightful Presence. It then makes five attacks: one with its bite, two with its claws, one with its horns, and one with its tail. It can use its Swallow instead of its bite.

Bite. Melee Weapon Attack: +19 to hit, reach 10 ft., one target. Hit: 36 (4d12 + 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: 28 (4d8 + 10) slashing damage.

Horns. Melee Weapon Attack: +19 to hit, reach 10ft., one target. Hit: 32 (4d10 + 10) piercing damage.

Tail. Melee Weapon Attack: +19 to hit, reach 20ft., one target. Hit: 24 (4d6 + 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 the Avatar of Extermination's choice within 120 feet of it and aware of it must succeed on a DC 17 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 the Avatar of Extermination 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 the Avatar of Extermination's Frightful Presence for the next 24 hours.

Swallow. The Avatar of Extermination 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 Avatar of Extermination, and it takes 56 (16d6) acid damage at the start of each of the Avatar of Extermination's turns.

If the Avatar of Extermination takes 60 damage or more on a single turn from a creature inside it, the Avatar of Extermination 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 the Avatar of Extermination. If the Avatar of Extermination dies, a swallowed creature is no longer restrained by it and can escape from the corpse by using 30 feet of movement, exiting prone.

Breath Weapons (Recharge 10):

Fire Breath. The Avatar of Extermination exhales fire in a 200-foot cone. Each creature in that area must make a DC 21 Dexterity saving throw, taking 99 (15d10) fire damage on a failed save, or half as much damage on a successful one.

Weakening Breath. The Avatar of Extermination exhales gas in a 60-foot cone. Each creature in that area must succeed on a DC 21 Strength saving throw or have disadvantage on Strength-based Attack Rolls, Strength Checks, and Strength Saving Throws for 1 minute. A creature can repeat the saving throw at the end of each of its turns, Ending the Effect on itself on a success.

Lightning Breath. The Avatar of Extermination exhales lightning in a 90-foot line that is 5 feet wide. Each creature in that line must make a DC 19 Dexterity saving throw, taking 66 (12d10) lightning damage on a failed save, or half as much damage on a successful one.

Repulsion Breath. The Avatar of Extermination exhales repulsion energy in a 30-foot cone. Each creature in that area must succeed on a DC 19 Strength saving throw. On a failed save, the creature is pushed 60 feet away from the Dragon.

Cold Breath. The Avatar of Extermination exhales an icy blast in a 60-foot cone. Each creature in that area must make a DC 20 Constitution saving throw, taking 58 (13d8) cold damage on a failed save, or half as much damage on a successful one.

Paralyzing Breath. The Avatar of Extermination exhales paralyzing gas in a 60-foot cone. Each creature in that area must succeed on a DC 20 Constitution saving throw or be Paralyzed for 1 minute. A creature can repeat the saving throw at the end of each of its turns, Ending the Effect on itself on a success.

The Avatar of Extermination can take 5 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. The tarrasque regains spent legendary actions at the start of its turn.

Attack. The Avatar of Extermination makes one claw attack or tail attack.

Move. The Avatar of Extermination moves up to half its speed.

Chomp (Costs 2 Actions). The Avatar of Extermination makes one bite attack or uses its Swallow.