Seed of a Dying Star

Reality Absorption. The Seed absorbs any aspects of reality that its flesh touches, incorporating those aspects into itself. At the start of the encounter, players should write a paragraph or two describing their characters. Objects that strike its flesh lose one word used to describe it, and the seed collects that word. If an object has no words to describe it, it ceases to exist.

Over-Healing. The Seed has no maximum hit points. It can heal past its starting total.

Drifting Tendrils. The Seed starts the encounter with a number of Tendrils equal to the number of players sitting at the table. At the start of each of its turns, it regenerates any missing Tendrils, then grows a new one. Tendrils have 10 AC, and can be destroyed with 15 or more damage. If there are multiple Seeds in this encounter, the number of Tendrils is shared between them.

Germinate. At the start of the Seed's turn, if a Seed of a Dying Star has twice as many hit points than its starting total, or if it has as many words collected as it does words to describe it, it attempts to germinate.
The Seed drops all creatures grappled by it, and begins to burrow into the earth at a speed of 30 ft per round. A seed in this state doesn't grow any new Tendrils through Drifting Tendrils, and ignores all other creatures. It also heals 3d10 at the start of its turns.
When a Seed reaches the world's core, it slowly feasts on the world, until it is the only thing remaining. Then, it uses everything it ate to become a new, living, world.

Action Points. The Seed has a number of Action Points equal to the number of Tendrils. These Action Points are shared between all Seeds in this encounter.

Multi-attack. The Seed makes two Tendril attacks, then Siphons Reality.

Tendril (1 Action Point). Melee Weapon Attack: +5 to hit, reach 20 ft., 1 target. Hit: 5 (1d10) bludgeoning damage. The target is then grappled (escape DC 15).

Displace Tendril (1 Action Point). The Seed displaces one of its tendrils, causing it to appear next to a creature within 300 ft. The tendril remains in this place until it is retracted by the Seed, or otherwise destroyed. A displaced Tendril can only be used for the Tendril attack, and Siphon Reality.

Tendril Storm (3 Action Points). An area within 300 ft, with a radius of 15 ft, becomes filled with whirling tendrils. Creatures within this radius must make a DC 15 Strength saving throw, or take 3d10 bludgeoning damage and become grappled (escape DC 15).

Siphon Reality (1 Action Point). The Seed siphons the essence of creatures in its grasp. Each creature grappled by the Seed loses 1d4 words that could be used to describe them, and then the Seed collects those words and heals itself by that many hit points. If a creature has no words left to describe them, they cease to exist.

Dislocate (4 Action Points). The Seed appears to shift to a location within its movement range. In reality, it hasn't even moved. This false movement ends the Seed's turn immediately. At the beginning of the Seed's next turn, this false movement becomes reality, and the Seed is now in the location it appeared to have been at the end of the previous turn. A successful DC 20 Perception (Wisdom) check betrays the Seed's true location.

Creation (3 Action Points). The Seed uses three of the words it has collected to construct a new creature or object using those words. These words are spent, contained within the newly constructed Creation.
A Creation has enough intelligence to participate in combat, but doesn't understand any language, and is only loyal to the Seed that created it. Creations have 3d10 hit points, 12 AC, and deal 1d8 damage (bludgeoning, piercing, or slashing) on a successful attack.
If a Creation is destroyed, the words used to create it float in the air where it was destroyed, and can be collected by any character as an action. These words can then be spent as a bonus action to add to that character's description, add to an adjacent character or object's description, or to make a new Creation. This Creation is loyal to its creator.