Announced Enviromental Units news - Terra Centauri: Last Stand Game
Aside from the main factions, there are other lifeforms, and intractable objects scattered across the world of Terra. Some of these are very valuable for the player. As a general rule these are randomly scattered throughout the stage on each play through (there are some exceptions) so the levels is never the same twice.
Terra Centauri Enviromental/Neutral Unit List
Check out environmental and neutral units currently in Terra: http://www.indiedb.com/games/terra-centauri-last-stand/news/announced-enviromental-units