Borg colony ship

The Borg colony ships were a new type of vessel employed by the Borg Collective in its attempted assimilation of the Alpha Quadrant. Several of these vessels were used to assimilate a planet within the Regula Badlands.

These pyramid shaped vessels would orbit a planet and fire a powerful planetary assault beam which would eliminate cities and defenses. After which, the ship would rotate to allow the bottom part of the vessel to beam down Borg Drones to the surface to transform the planet into a Borg colony.

Beyond this, they possessed little in the form of defenses and were vulnerable to attacks by enemy ships.

(TNG video game: Armada II)