Slicing through the inky blackness of space, a brilliant blue sapphire of reverence traveled, its angular mass reflecting the thin jasmine beams of light that touched its smooth surface. To some worlds, this may seem nothing more than bewildering sight, but to others it was a vision of death. From within the confines of the Space Hunter Nebula M's twisted and primordial minds, the birth of a cyborg, dubbed Gigan, was born. Housed within its gem lair, the creation was sent to the furthest corners of the universe, missions of utter destruction and mayhem programmed in its soulless heart.

In 1972, the cyborg, along with King Ghidorah, left for earth. Laying a swath of broken bodies, and rivers of innocent blood in their wake, the duo made their presence known on Earth. No weapon of man stood a chance against the space demons. Anything thrown at them were just more useless lives that were feed into the blazing inferno. It wasn't until Godzilla and Anguirus arrived from Tokyo Harbor, that the devils met a challenge. However, with the space creatures working in perfect unison from the Nebulan's control, Godzilla and Anguirus could not prevail. Only through the assistance of mankind could the terrestrial behemoths win. Realizing that defeat was likely, Gigan ascended from Earth, followed closely by the recently pummeled King Ghidorah.

However, the cyborg's duty wasn't finished yet. Following in the Nebulan's footsteps, the race of an undersea people, the Seatopians, quickly launched an all out assault on the weakened earth forces with their god Megalon. Knowing that a quick and powerful strike was the key to victory, the Kingdom of Seatopian sent out a plea for the Space Hunter M aliens to send Gigan. Answering the call, the aliens complied and the cyborg was sent back to Earth. However, once again, as fate would have it, the pair of Megalon and Gigan met resistance. The combined strength of Godzilla and Jet Jaguar was more than enough to detour the pair of demons. Gigan, realizing that defeat was immanent, fled from Earth, leaving Megalon to face the overwhelming dominate power of Godzilla and Jet Jaguar alone.

Traveling through the voids of space, the weakened Gigan crossed paths with the Garoga. Capturing the cyborg, the alien race equipped Gigan with modifications, placing explosives in the clawed forearm tips. Ready for battle, the monster was parachuted back to Earth. Placing its steel clawed feet on the soft soil, the red eyed cycloptic creature faced a familiar adversary: Godzilla. The reissuing battle between Gigan and the King of the Monsters was again fought. Even with his new abilities, though, Gigan was no challenge for Godzilla. Dispensing with the cyborg, the leviathan left Gigan for dead after rescuing Zone Fighter. However, Gigan was not finished, and rose once more to fight Zone Fighter. The two battled, but the cyborg's previous war had taken a toll on its strength. Releasing his signature Meteor Missile Might attack, the humanoid giant destroyed the creature for good.