Colossal Nature. The Voidwoken Tarrasque occupies a space between 25-foot-by-25-foot up to 100-foot-by-100-foot (DM's choice). It is immune to difficult terrain and is unaffected by forced movement. It is also immune to the prone, grappled, restrained, and exhaustion conditions.

Void-Tainted. At the end of each of its turns, the damage dice for all its attacks increases by one. All of its attacks are considered critical hits and deal maximum damage. All of its attacks inflict the Incapacitated condition.

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

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

Innate Immortality. If the Voidwoken Tarrasque is killed, it is merely banished to a secret pocket dimension within the void for $1\text{d}100$ years, after which it returns to life in a location of the DM's choosing.

Reality Anchor. It cannot be imprisoned, banished, or wished away. It is unaffected by spells such as wish or other reality-altering spells and magic.

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 tarrasque deals double damage to objects and structures.

Necrotic Affliction. The Voidwoken Tarrasque's physical attacks deal an additional $9\text{d}6$ necrotic damage. All of the Voidwoken Tarrasque's attacks are considered magical and bypass damage resistances and immunities.

Aura of Erasing. The Voidwoken Tarrasque has a reality-erasing aura with a range of $10\text{ feet}\times 9=90\text{ ft}$. Any magical constructs or creatures summoned by a spell that start their turn within the aura are destroyed. Within this aura, all damage immunities of its enemies are negated. No creature can be healed while inside the aura.

Earth Glide. The Tarrasque can burrow through nonmagical, unworked earth and stone. While doing so, it doesn't disturb the material it moves through.

Unfettered Existence. The Tarrasque is immune to being banished and to the restrained condition.

Magic Weapons. The Tarrasque's attacks are considered magical for the purpose of overcoming damage resistance and immunity.

Unburdened Movement. The Tarrasque ignores movement penalties from being underwater, difficult terrain, or similar environmental effects.

Reactive Adaptation. The Tarrasque has 9 stored damage resistances, starting with resistance to bludgeoning, piercing, and slashing damage from nonmagical attacks. When the monster takes damage of a type it is not resistant to, it gains resistance to that damage type and loses its oldest stored resistance. If it takes damage of a type it is already resistant to for a second consecutive time within a single round, it becomes immune to that damage type for 1 minute, or until it is hit by a new damage type, at which point the immunity is replaced. This monster can only have up to two damage type immunities at a time through this trait.

Multiattack. The tarrasque can use its Frightful Presence. It then makes five attacks: one with its bite, two with its claws, one with its horn, and one with its tail.

Bite. Melee Weapon Attack: +19 to hit, reach 20 ft., one target. Hit: 36 (4d12 + 10) piercing damage plus 31 ($9\text{d}6$) necrotic damage. If the target is a Large or smaller creature, it is swallowed. A swallowed creature is blinded and restrained, and it has total cover against attacks and other effects outside the tarrasque.

Swallow (Three Stomachs)

A swallowed creature progresses through the Tarrasque's three stomachs, spending 2 turns in each of the first two before moving to the next. The creature takes damage at the start of each of the tarrasque's turns, depending on its current location:

1. First Stomach (Corrosive Cauldron): The creature takes 42 ($12\text{d}6$) acid damage.

   • To be regurgitated, the Tarrasque must take 60 damage or more from creatures inside this stomach on a single turn.

2. Second Stomach (Void-Infused): The creature takes 156 ($24\text{d}12$) necrotic damage.

   • To be regurgitated, the Tarrasque must take 120 damage or more from creatures inside this stomach on a single turn.

3. Third Stomach (Boiling Assimilation): A creature that enters this stomach is instantaneously destroyed and assimilated by the Voidwoken Tarrasque, with no saving throw allowed.

If the Tarrasque takes the required damage (60 for the first stomach, 120 for the second) on a single turn, it 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 Tarrasque. If the Tarrasque dies, a swallowed creature is no longer restrained by it and can escape from the corpse using 15 feet of movement, exiting prone.

Claw. Melee Weapon Attack: +19 to hit, reach 15 ft., one target. Hit: 28 (4d8 + 10) slashing damage plus 31 ($9\text{d}6$) necrotic damage.

Horn. Melee Weapon Attack: +19 to hit, reach 20 ft., one target. Hit: 32 (4d10 + 10) piercing damage plus 31 ($9\text{d}6$) necrotic damage.

Tail. Melee Weapon Attack: +19 to hit, reach 20 ft., one target. Hit: 32 (4d10 + 10) bludgeoning damage plus 31 ($9\text{d}6$) necrotic 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 tarrasque'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, 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 tarrasque's Frightful Presence for the next 24 hours.

Voidic Roar (Recharge 5-6). The Tarrasque unleashes a roar that tears at reality. Each creature within a 60-foot cone must make a DC 20 Constitution saving throw. On a failed save, a creature takes 55 ($10\text{d}10$) force damage and is incapacitated until the end of its next turn as parts of its body briefly cease to exist. On a successful save, the damage is halved, and the creature is not incapacitated.

Void Beam (Recharge 5-6). The Tarrasque projects a 240-foot cone of pure void energy. Each creature in the cone must make a DC 27 Constitution saving throw. On a failed save, a creature takes 78 ($12\text{d}12$) force damage and 78 ($12\text{d}12$) necrotic damage and is incapacitated for 1 minute. On a successful save, a creature takes half damage and is not incapacitated. The incapacitated creature can repeat the saving throw at the end of each of its turns, ending the effect on itself on a success.

The tarrasque 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. The tarrasque regains spent legendary actions at the start of its turn.

Attack. The tarrasque makes one claw attack or one tail attack.

Move. The tarrasque moves up to half its speed.

Swallow (Costs 2 Actions). The tarrasque makes one bite attack. If the attack hits, the target is swallowed.