The House of Leaves

On Threia, there is a human culture that calls itself the House of Leaves. (A direct nod to Danielewski)  The humans there live in direct symbiosis with the native Thriean and the forest around them

The Threian are creatures of vine, leaf,moss and wood, evolved into sentience by contact and consumption of Astral material. Like all things touched by the Astral plane.

In their natural form they look something like a squid. They move in three dimensions through the massive forests they call home, pulling themselves through the trees and across the ground with hundreds of tentacle-like vines. [The Mimics from Edge of Tomorrow](https://youtu.be/iiKeTPL6HPk) are pretty spot on as to how I imagine the Threian are shaped and move and fight.

Their psychology is somewhat hive-mind-esque, though each Threian posses individuality, their capability for everything from sentience to emotion is directly related to their age and the amount of Astral material they've collected.

They have a limited capability to reshape themselves - aside from the capabilities given by being made of pliant plant material. They form faces for themselves when in the presence of humans, so that they might speak and better show emotion. They are also known to take a humanoid shape when working closely with another human, seeking to make them more comfortable.

They are able to separate parts of themselves, which is part of how they procreate, but without enough Astral Material, those pieces are only 'intelligent' enough to follow simple programmed instructions.

Threian reproduce when they have enough excess Astral material collected to give sentience to another separate entity.

This leads into how they get along with the humans of The House of Leaves. The humans help to cultivate the Threian and the Threian themselves make up the majority of the materials the humans use. Everything from clothing and armor to tools, weapons and even their very housing is made up from what was once Threian anatomy. The Threian grow these things, sometimes even taking years to complete.