The Space Monsters (aka, Uchuu Kaijuu = 宇宙怪獣) are an eldritch race of spaceborne insectoid giants in the Gunbuster universe which feed on stars and destroy sentient life. An eldritch insectoid race that destroys any sentient life in the galaxy.

Space Monsters I (Gunbuster)


It is theorized that the Space Monsters serve as the antibodies of the galaxy and perhaps the universe, exterminating parasitic lifeforms (sentient life). Human scientists base this on the fact that humanity has not encountered any other lifeforms in the galaxy.


Wherever humanity has encountered the Space Monsters it has ended in battle as the insectoids attempt to exterminate the humans. War began in 2015 AD and to fight against the giant insects the human race built giant piloted robots and warp capable warships.

Eventually, the humans were able to defeat the Space Monsters by using a planetoid-sized bomb that was detonated at the center of the galaxy. It sucked in all of the Space Monsters and for 12,000 years the human race was the only sentient lifeform in the galaxy resulting in the expansion of human civilization throughout the galaxy. At the end of the 12,000 years they faced the threat of a single planet-sized Space Monster powered by that same black hole. It was defeated by a force of titanic piloted robots.

Space Monsters III (Gunbuster)


The insectoids come in a wide variety of forms and sizes. The smallest of them are the size of huge tanks and fighters. Starship analogs are miles or city-sized. The motherships are the size of moons and the final Space Monster was the size of a gas giant planet (30,000 km long).

Space Monsters reproduce by laying eggs in stars. While in the star, the eggs drain energy from the star and once they hatch and become mature, they leave the star. In the process prematurely aging the star to such an extent that a yellow G-Class star becomes a red giant within a few years after they leave the star.


The giant insectoids have the following capabilities and weapons:

  • Tracking enemy vessels or fleets that are in sub-space (warp)
  • Battling enemy vessels or fleets that are in sub-space (warp)
  • Plasma bio-cannons
  • Spike-like projectiles which pierce the armor of Terran warships
  • Drones used in swarms of 100s
  • Capital ships, with plasma energy beams that blast through planets and destroy enemy warships on the other side of the world
  • Using a black hole as a power source
Space Monsters IV (Gunbuster)


Space Monsters rely on overwhelming human fleets. In battle, the humans face wave after wave of Space Monsters, each wave with billions of insectoids. A Space Monster fleet is so large that it occupies as much space as a gas giant planet.

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