Constrictor Hive Mind

Venomous Fury: Up to twice per day the Constrictor Hive Mind may use an action to cover a 10 ft. radius (centered on the Constrictor Hive Mind) in a poisonous acid. Any creature within this radius must make a DEX 12 Saving Throw. On a fail, the creature takes (4d6) poison damage, or half that on a save.

Venemous Fury (Undead): Once per day the Constrictor Hive Mind (Undead) may use an action to cover a 10 ft. radius (centered on the Constrictor Hive Mind [Undead]) in a poisonous acid. Any creature within this radius must make a DEX 8 Saving Throw. On a fail, the creature takes (2d6) poison damage, or none on a save.

Adaptive Skin: At the beginning of its turn, the Constrictor Hive Mind regains 9 (1d10 + 3) health.

Adaptive Skin (Bloodied): At the beginning of its turn, the Constrictor Hive Mind (Bloodied) regains 20 (2d12 + 7) health.

Adaptive Skin (Undead): At the beginning of its turn, the Constrictor Hive Mind (Undead) regains 12 (1d12 + 5) health.

Bloodied Fury: When the Constrictor Hive Mind is reduced to less than half its max health, the following effects become active (Bloodied Fury is nullified completely when the Constrictor Hive Mind moves to the "Undead" phase):
Bloodied Fury (Fearful Resistance): The Constrictor Hive Mind gains resistance to piercing, bludgeoning, and slashing damage dealt by non-magical weapons.
Bloodied Fury (Resources Run Dry): The Constrictor Hive Mind's "Snake Bites" attack enters the "Bloodied" phase.
Bloodied Fury (Crisis Incoming): The Constrictor Hive Mind's "Adaptive Skin" trait enters the "Bloodied" phase.

Snake Bites: The Constrictor Hive Mind can use its action to perform eight snake bite attacks of either melee, ranged, or a mix of both.
Snake Bites (Melee): +5 to hit, reach 5 ft., one creature. Hit: 8 (1d6 + 4) piercing damage.
Snake Bites (Ranged): +4 to hit, reach 20/40 ft., one creature. Hit: 6 (1d6 + 2) piercing damage.

Snake Bites (Bloodied): The Constrictor Hive Mind (Bloodied) can use its action to perform six snake bite attacks of either melee ranged, or a mix of both.
Snake Bites (Melee): +6 to hit, reach 5 ft., one creature. Hit: 9 (2d6 + 2) piercing damage.
Snake Bites (Range): +2 to hit, reach 10/20 ft., one creature. Hit:  6 (2d4 + 1) piercing damage.

Snakes Bites (Undead): The Constrictor Hive Mind (Undead) can use its action to perform four snake bite attacks of either melee, ranged, or a mix of both. Alternatively, the Constrictor Hive Mind (Undead) can perform two life drain snake bite attacks.
Snake Bites (Melee): +5 to hit, reach 5 ft., one creature. Hit: 10 (2d4 + 5) piercing damage.
Snake Bites (Ranged): +3 to hit, reach 15/30 ft., one creature. Hit: 8 (1d8 + 3) piercing damage.
Snake Bites (Life Drain): +4 to hit, reach 5 ft., one creature. Hit: 9 (2d6 + 4) necrotic damage. On a successful hit, the Constrictor Hive Mind (Undead) heals half of the damage dealt.

Slithery Identity: The Constrictor Hive Mind man take an entire turn to form itself into a shape similar to another large creature and then casts Disguise Self on itself to assume the physical identity of said creature.

Hide or Snake: The Constrictor Hive Mind, despite their large size, can fit within a 5 ft. cube and hide their with a natural stealth of 18.

Eye of the Storm:  When the Constrictor Hive Mind loses more than half of its current health, the Constrictor Hive Mind may immediately cast Misty Step, the range of which is increased to 45 ft.

Panic Tactics: When the Constrictor Hive Mind is within 5 ft. of 4 or more enemies at one time, the Constrictor Hive Mind may immediately use three attacks (from the corresponding "Snake Bites" list) and then activate "Eye of the Storm."

Constrictive Escape: When 2 or more creatures make an opportunity attack of the Constrictor Hive Mind during its turn, the Constrictor Hive Mind can choose one enemy to automatically fail their attack role.

Eye of the Lost: The first time the Constrictor Hive Mind reaches 0 health, the Constrictor Hive Mind will immediately regain 26 (6d6 + 5) health, enters the "Undead" phase, and may then immediately take the "Snake Bites (Undead)" attack action. 
--> [Upon reaching 0 health after this ability has already been used, the Constrictor Hive Mind (Undead) may make a CON 12 saving throw to activate the ability again. The DC increases by 4 each time the creature reaches 0 health after reactivation of this ability.]