Corporeal Instability. Any creature that is hit by the chaos beast’s claw attack, or takes damage from being engulfed by it must succeed on a DC 18 Charisma saving throw or become a spongy, amorphous mass. The affected creature is unable to hold or use any item. Clothing, armor, and equipment become useless.
The creature’s speed is reduced by 10 feet. Searing pain courses along the nerves, so strong that the creature cannot act coherently; it cannot cast spells or use magic items, and it attacks blindly, unable to distinguish friend from foe. At the start of the creature’s turn, roll a d8 to determine what it does during its turn. On a 1 to 4, the creature does nothing. On a 5 or 6, the creature takes no action or bonus action and uses all its movement to move in a randomly determined direction. On a 7 or 8, the creature makes a melee attack against a randomly determined creature within its reach or does nothing if it can’t make such an attack.
Each round that the creature spends in an amorphous state, its Wisdom is reduced by 1. The target becomes a chaos beast if this reduces its Wisdom to 0.
A creature can repeat its saving throw at the end of each of its turns, ending the effect on itself with a success. A greater restoration spell or similar magic removes the affliction. And a separate greater restoration spell is required to restore any lost Wisdom.
Immutable Form. The chaos beast is immune to any spell or effect that would alter its form.
Shapechange. The chaos beast can use a bonus action to change its form to one of the following when it has more than 25% of its HP, if it has less than 25% if HP it is stuck in the Fleshy mass form:
Multiattack. The chaos beast makes two claw attacks. (five claw attacks if in Tendrilled form)
Claw. Melee Weapon Attack: +10 to hit, reach 15 ft., one target. Hit: 15 (2d8 + 6) slashing damage.
Engulf. The chaos beast moves up to its speed. While doing so, it can enter Large or smaller creatures’ spaces. Whenever the chaos beast enters a creature’s space, the creature must make a DC 18 Dexterity saving throw.
On a successful save, the creature can choose to be pushed 5 feet back or to the side of the chaos beast. A creature that chooses not to be pushed suffers the consequences of a failed saving throw.
On a failed save, the chaos beast enters the creature’s space and the creature takes 24 (4d8 + 6) piercing damage and is engulfed. The engulfed creature can’t breathe, is restrained, and takes 24 (4d8 + 6) piercing damage at the start of each of the chaos beast’s turns. When the chaos beast moves, the engulfed creature moves with it.
- Fleshy mass. The chaos beast has a fleshy mass, two tentacle like arms that change between clawed fingers or biting mouths on the ends. It's body has multiple eyes looking for targets and threats.
- Armored shell. The chaos beast becomes immobile and blind as it makes it skin into a bone-like matter. it's AC is 18 when armored and it is unable to attack until taking another form. it has Disadvantage on dex saves.
- Tendrilled. its core shrinks and it creates up to 5 50ft tendrils that tries to slash those around it. it's has less eyes and is unable to move. AC becomes 12 and has Disadvantage on dex saves.
- Gaping maw. A giant mouth forms allowing the chaos beast to engulf anyone unlucky enough to be near. it is unable to attack with its tendrils when gaping. Its body is now full with eyes but no arms for attacking.
- Crawler. The chaos beast creates a massive amount of legs under it, giving it advantage on dex saves and allows it to take the dash action as a bonus action. it only has a single tentacle/ arm protruding from its body.
- Eyed. Focusing entirely on perception it has advantage on all perceptions checks. It's AC is 15 but it is unable to attack.
Immutable response. as a Reaction the chaos beast targets a single enemy attacking it and gives it the Corporeal Instability effect on a failed save.
Defensive respons. When targeted by a spell or attack the chaos beast, it can use a reaction to turn to it's Armored shell form.