The Hive is a convention of alien races that have come together. They are led by the Vortaak. The Hive has several alien kaiju that are used as war machines. They appear in the Godzilla vs. Mukozilla trilogy.
- Space Hunter Nebula M
- King Ghidorah: The Xillien's leader of the alien kaijus, King Ghidorah is the single most dangerous living being in the universe. He has destroyed and/or conquered many planets under the bidding of the Hive. He is the mortal enemy of Godzilla, and will stop at nothing do destroy him, the Powerpuff Girls, Mukozilla, and the Earth itself. His weapons include his gravity beams that he fires out of his mouth. Utilizes the 1991 design from Godzilla vs. King Ghidorah with a brighter gold color.
- Gigan: The Space Hunter Nebula M's second-in-command of the alien kaijus, Gigan is a ruthless, kaiju assassin that will stop at nothing to kill Godzilla. His mortal enemy is Dynamo of the Global Defense Force, due to their ranks and fighting styles. Gigan's weapons include his eye laser, abdomen buzz-saw, and his deadly arm-scythes. He can be modified into his Chainsaw Gigan form, which includes a different head and replaces the scythes with dual-chainsaws. Formerly utilized his 1972 design from Godzilla vs. Gigan, now utilizes his 2004 design from Godzilla: Final Wars.
- Hedorah: An alien sludge monster that fought Godzilla once and lost. A second Hedorah soon emerged and left Earth, and was found by the Cryogs and was genetically manipulated to withstand radioactivity, making it very difficult for Godzilla to battle. Hedorah's body is virtually a weapon in itself, as it is corrosive. He can switch between his microscopic, land, flying, underwater, and final forms. He also has eye laser beams. Utilizes his 1971 design from Godzilla vs. Hedorah.
- Orga: The Millennians powerhouse of the alien monsters, Orga is actually very intelligent, so much, in fact that it actually rivals human intelligence alone. However, Orga is more favored for his strength rather than his intelligence. His weapon include his venomous maw, which can extend to swallow prey whole, his shoulder cavity that fires a laser, and his massive hands, which can lift Godzilla up off of the ground. Utilizes his design from Godzilla 2000: Millennium (1999).
- SpaceGodzilla: The intergalactic clone of Godzilla, SpaceGodzilla is a very dangerous kaiju, although not on King Ghidorah's level, and could easily rip the Earth in two if he so desired. His weapons include telepathy, telekinesis, levitation, can manipulate and control crystals for both protection and attack, and a corona beam that can be fired from his maw. However, his most dangerous weapon is his disturbingly human-level intelligence, which makes him an extremely dangerous enemy. Utilizes his design from Godzilla vs. SpaceGodzilla (1994).
- Megalon: The Seatopian beetle god of the underground, Megalon is a rather unintelligent kaiju that is often paired with Gigan. However, point him in the right direction, and everything from a 90-150 mile radius will be utterly destroyed. Megalon's weapons include his arm mounted drills, his fireballs that he spits from his mouth, and his incredible burrowing ability. Utilizes his design from Godzilla vs. Megalon (1973).
- MechaGodzilla: The Simeons original robotic-clone of Godzilla that was once sent to Earth to destroy Godzilla during their alien invasion, back when Godzilla was an anti-hero. Godzilla and MechaGodzilla fought, but the latter was destroyed and the Earth was safe. However, the Simeons regained some of the technology used to construct the first MechaGodzilla and have since rebuilt and modified it. It's weapons include finger, knee, and toe missiles, a chest laser, eye-lasers, flamethrower-nostrils, and it's head can spin 360 degrees to face sneaky enemies or to create a force-field. Utilizes it's 1975 design from Terror of MechaGodzilla.