SpaceGodzilla's origins in the film are not concretely stated, as the human characters in the film suggest two possibilities for how the monster came to exist, although both versions suggest one common thread. The first is that Godzilla cells were sent into space when Biollante departed the planet after her battle with Godzilla in the 1989 film Godzilla vs. Biollante. The other possibility is that Mothra took Godzilla cells into space when she departed the planet in order to destroy a massive asteroid which was supposedly going to impact the planet in 1999 in the 1992 film Godzilla and Mothra: The Battle for Earth. Both origins describe these Godzilla cells as being sucked into a Black Hole and heavily altered, then being returned to our universe via a White Hole.
When Spacegodzilla was adapted for Trendmasters' Godzilla Wars toyline, his origin was changed. Biollante was now the definitive cause of the Godzilla cells finding their way into space, but instead of being sucked into a black hole, they instead encountered and fused with a crystalline entity, which then became Spacegodzilla. This version of Spacegodzilla, like his film counterpart, immediately made his way to Earth with the singular purpose of defeating/destroying the original Godzilla.
In the Doom Island line of figures, SpaceGodzilla was to battle two Ankylosaurs in a monster vs. dinosaur pack.
SpaceGodzilla possesses powers similar to those of Godzilla, including the benefits of Godzilla's physical near-invulnerability and atomic breath. The crystals extending from his shoulders grant SpaceGodzilla control over gravity; allowing SpaceGodzilla to fire gravity beams like those used by King Ghidorah from them, levitate himself or other objects, or even hurl his enemies through the air. As his power derives from cosmic energy, SpaceGodzilla can strengthen himself by materializing crystalline growths out of the ground to turn the Fukuoka Tower into a massive energy conduit. These crystals can also be used by SpaceGodzilla as impromptu projectiles through the use of his gravity manipulation or even as a cage which he used to imprison Little Godzilla. Other powers include a crystal force field strong enough to deflect Godzilla's atomic breath and the ability to encase himself within a harness of crystals which sprout from its back. While in its crystalline form, SpaceGodzilla gains powers of flight as well as increased defensive/offensive abilities.
During its battle against the anti-Godzilla robot Moguera in the asteroid belt, the crystals blocked the machine's plasma lasers and carved deep gashes into Moguera's hull with their sharpened points. SpaceGodzilla's crystalline form is also capable of firing gravity beams in any direction and can also cause disruptions in electrical equipment as it flies overhead. SpaceGodzilla's tail is surprisingly strong, as he managed to stab his tail through Moguera as well as release a burst of energy into Moguera through his tail. Finally, SpaceGodzilla seems to have the ability to home in on Godzilla himself; first landing on Birth Island, where Godzilla and his son reside.
Unlike Godzilla, who in the Heisei series of films is depicted as a force of nature, and being neither good nor evil, SpaceGodzilla appears to have an element of true malice, as the monster was said by the Cosmos to be headed to Earth for the purpose of killing Godzilla. According to the cosmos, SpaceGodzilla was planning to kill Godzilla so that he could dominate the Earth. Like Biollante upon defeat, SpaceGodzilla's physical body changed into particles of energy.
Much like many other monsters of the Heisei era, SpaceGodzilla's roar is recycled- Gigan's roar is used and lowered in pitch.
SpaceGodzilla was an older idea that was originally planned to continue the Showa series (along with Godzilla vs. the Devil) after Terror of Mechagodzilla, but which had been scrapped. The concept would be pulled from obscurity in 1994, following the failure of TriStar Pictures to begin production on a planned Hollywood Godzilla film, which would be another four years in the making. The design was based on an alternate form of Godzilla featured in the 1993 Super NES videogame Super Godzilla; the design was reworked to incorporate crystals into the kaiju's form.
Original versions of the script called for SpaceGodzilla to face Godzilla and a second Mechagodzilla, a plan scrapped when it was realized that against the combined might of Godzilla and the machine which very nearly killed him the previous year would make the battle too one-sided. Instead, Moguera was revived and updated for this purpose.
SpaceGodzilla also appeared in Godzilla: Giant Monster March for the Game Gear.
SpaceGodzilla was considered for Godzilla: Destroy All Monsters Melee, But he was scrapped due to 2 Godzilla's were being already in the game and it was the same has Godzilla 1954 and the Fighting Roster size was shorted.
SpaceGodzilla's made another appearance in Godzilla: Save the Earth. He replaces Orga as the final opponent in hard mode. It can be implied that the Vortaak, after their defeat in Godzilla Destroy All Monsters Melee, ran into SpaceGodzilla and made a deal with him: SpaceGodzilla would control all of the monsters under the Vortaaks control using his psychic abilities as well as control the monsters on Earth and help the Vortaak conquer Earth and in the return, the Vortaak would give SpaceGodzilla control of the entire planet. In the game's climax Godzilla blasts off SpaceGodzilla's shoulder crystals causing a black hole to form. SpaceGodzilla is sucked in and is seemingly destroyed forever. Though later it is revealed that he simply became trapped in the black hole.
SpaceGodzilla returned in Godzilla: Unleashed as the final boss in story mode and the game's main antagonist. In the PlayStation 2 version, he is responsible for the crystals, and probably Obsidius' and Krystalak's creator. After being imprisoned in Save the Earth, SpaceGodzilla tried to escape his prison, causing the crystals appearing across the planet. In the Wii version, he uses the crystals' radiation to escape his prison but is defeated by the combined efforts of the Earth Defenders and GDF.
Two alternative endings include the mutants win and Spacegodzilla takes over the world and the aliens win and kill SpaceGodzilla and use his energy to empower their monsters.