Aennri, the Green Autocracy
The Aennri Civilization does not figure greatly in most interstellar wars. Their primary desire is to be left alone. Their StarShip has been either hidden or destroyed, and they hide their colonies on forest and jungle worlds, using an advanced stealth technology to hide themselves from enemy scanners.
The Aennri have an almost supernatural ability to blend in with their natural surroundings. Their bases are indistinguishable from rocks and trees. In battle, they use BoobyTraps and hit-and-fade ambushes to divide enemy forces, cut them off from supplies and reinforcements, and whittle away at their numbers.