The M Space Hunter Nebula Aliens, known as the Nebulans for short, are an insectoid alien race and the villains of the 1972 film Godzilla vs. Gigan. Inhabitants of a dying planet within the M Space Hunter Nebula, these aliens set their sights on Earth, establishing a front for their invasion in the World Children's Land amusement park. The Nebulans summoned both Gigan and King Ghidorah to assault the Earth, but their plans were foiled by the combined efforts of Godzilla, Anguirus, and a ragtag group of humans. The following year, the Nebulans loaned Gigan to the Seatopians to aid their monster Megalon against Godzilla and Jet Jaguar.
Godzilla vs. Gigan
An advanced race similar to humans once inhabited the Nebulans' home planet within the M Space Hunter Nebula. However, the pollution they produced eventually wiped them out, leaving behind a species of cockroach-like creatures which evolved into the planet's dominant lifeforms. However, the damage done to their planet's environment was too great, and the planet's days were numbered. With no other option, the Nebulans set out to find a new home. They eventually discovered Earth, a planet very much like their own inhabited by a civilization similar to the one that came before them. The Nebulans assumed human disguises and constructed the World Children's Land to serve as a front for their planned invasion. The chairman of the invasion force assumed the identity of Fumio Sudo, while his assistant took on the identity of Kubota.
Kubota recruited struggling manga artist Gengo Kotaka to design monsters for World Children's Land. Kotaka immediately grew suspicious of the park and its promise of teaching children "absolute peace," along with its plan to wipe out Monster Island. Kotaka eventually met Machiko Shima and Shosaku Takasugi, who were trying to find Machiko's brother Takashi, who disappeared while working for World Children's Land. When Kubota and Sudo realized Kotaka was onto them, they attempted to capture him and his comrades only to be chased off by Kotaka's girlfriend Tomoko Tomoe. Tomoko joined the three in infiltrating the Godzilla Tower within World Children's Land, where they rescued Takashi Shima. However, the Nebulans discovered them and took them hostage. They revealed their true cockroach-like forms to the humans and explained how they came to Earth. They then summoned Gigan and King Ghidorah to lay waste to Tokyo in order to prepare humanity for conquest.
Godzilla and Anguirus escaped from Monster Island and made their way to Tokyo to stop the invaders' monsters. While they battled Gigan and King Ghidorah, the humans escaped the Godzilla Tower and worked with the JSDF to spring a trap for the Nebulans. They placed explosives in the Godzilla Tower elevator and covered them with a drawing of themselves, and sent it up to the top floor. The Nebulans immediately opened fire, triggering an explosion that destroyed the top floor. As Fumio and Kubota lay dying under the rubble, they reverted into their true forms and pondered what could have gone wrong with their plan. With the Nebulans and their base destroyed, Gigan and King Ghidorah ceased receiving orders from their masters and became confused, allowing Godzilla and Anguirus to turn the battle in their favor. Both space monsters soon retreated, and the Earth was saved from the Nebulans' invasion.
Godzilla vs. Megalon
When Jet Jaguar escaped the control of the Seatopians and went to Monster Island to recruit Godzilla's help against Megalon, the Seatopians requested that the Nebulans grant them the assistance of Gigan. The aliens obliged, deploying Gigan to Earth once again. However, Godzilla and Jet Jaguar overcame Gigan and Megalon, and the space monster retreated once again.
A Nebulan offered the assistance of Gigan to the Xilien agent Zagres, in order to help her take over Godzilla Island. When Gigan was driven off, Zagres squashed the Nebulan with a newspaper.
Godzilla: Rage Across Time
The Mongols, in actuality the Nebulans, invaded Japan in search of a new home. Using their advanced technology, they took control over Gigan and Megalon and used them to assault the Japanese forces. Godzilla soon appeared and defeated the Nebulans' monsters and destroyed their fleet with his atomic breath.
- In early story pitches for the comic series Godzilla: Rulers of Earth, the Nebulans served as the main antagonists. However, IDW was unable to use any human characters or alien races from the Toho films at the time and replaced the Nebulans with the Cryog. Likewise, the Devonian were originally the Seatopians in story pitches.