A Delta Quadrant species who seize inhabited worlds by bombarding them with artificial asteroids until the population flees, a scheme uncovered on a Nezu colony in Rise.
The Etanians appear in the Voyager episode Rise. Their government, the Etanian Order, has a practised method of taking territory without open war. It steers manufactured asteroids at a target planet, lets the inhabitants evacuate what looks like a natural catastrophe, and then arrives to claim the empty world.
In 2373 Voyager is helping a Nezu colony under such a bombardment, and its phasers fail to break the rocks up as they should. A Nezu scientist claims to hold proof of the cause, and Tuvok and Neelix crash while trying to reach him.
The survivors climb to orbit in a mag-lev carriage running up an orbital tether. On the way it emerges that the Nezu official Sklar is in the pay of the Etanians. The recovered data gives Voyager the weaknesses of the Etanian ships, which withdraw after a short fight.