Aside from Godzilla, Anguirus returns in this film and makes his final appearance until 2004's Godzilla: Final Wars. This film is notable for introducing Godzilla's robotic rival Mechagodzilla (who would return in four more Godzilla films), as well as King Caesar, who also returned in Godzilla: Final Wars.
According to an Okinawa legend, when a black mountain appears in the skies above the clouds, a monster will arrive and attempt to destroy the world. However, if this divination comes true, a red moon will set, two suns will arise (one being an optical illusion rising from the west), and two monsters will fight off evil to rescue the world. In a cave near the city, an engineer and an archaeologist uncover a statue of a strange lion-god creature, known as King Caesar. He is believed to be one of the monsters to fight for humankind in the prophecy. Later, a black mountain does appear in the sky. Godzilla then rises from a dormant volcano and starts on a rampage. Many people, however, do not believe Godzilla will be the monster to destroy Earth. That reflection is reinforced when Godzilla attacks Anguirus and nearly kills him. In a surprising turn of events, another Godzilla sets forth, only to discover that the rampant Godzilla is an impostor. Later revealed as MechaGodzilla, a robot of titanic proportions that was designed and created by ape-like aliens to destroy the original Godzilla. After Godzilla is beaten green and blue, he comes back, super charged with electricity, gathered from a lightning storm on Monster Island. With the help of the newly summoned King Caesar, Godzilla destroys MechaGodzilla and returns back to the sea.
The movie has become popular among fans in recent years for its campy music, colorful special effects and entertaining monster fights. The film's robust themes and fairly complex plot stand out against a time when the Godzilla franchise was being fueled by increasingly lower production values.
Outside of the circle, however, public reception is luke-warm at best and the movie garners only 5.4 stars (out of a possible ten) at IMDb.
The film sold approximately 1,330,000 tickets in Japan - modest business, but an improvement of about 350,000 over the previous Godzilla film, Godzilla vs. Megalon.
In 1977, Cinema Shares released the film originally in North America under the title Godzilla vs. the Bionic Monster. But due to the threat of a lawsuit against Cinema Shares from Universal Studios on account of supposedly deriving the title from The Six Million Dollar Man and The Bionic Woman, the movie was retitled Godzilla vs. the Cosmic Monster. But both variations of the American Poster were called the films original title. But the second variation later got the Cosmic Monster fix.
For the theatrical release, the film was kept with its original Hong Kong dubbing, and scenes were trimmed to receive a G-rating from the MPAA, mostly from the aliens' fistfights. The opening credits were altered as well. In 1988, New World Video released the film along with Godzilla 1985, Godzilla vs. Gigan, Godzilla vs. Megalon, and Children of the Corn. The print of the film that was shown in America would later be released on VHS, twice.
- Godzilla vs. Bionic Monster (original U.S. title)
- Godzilla vs. Cosmic Monster (U.S. theatrical title)
- Godzilla vs. RoboGodzilla
- The Robot Monster
- Technically, this is the first Godzilla film to feature a beam fight. It is not long, but it happens when Godzilla breathes atomic breath and MechaGodzilla shoots his eye beam. They lock for a few seconds before the combined rays explode sending Godzilla into the bay in pain and MechaGodzilla short-circuiting.
- Special effects director Teruyoshi Nakano adopted MechaGodzilla's walk from the formal movements of Kabuki.
- This was the 20th Anniversary Godzilla film.
- The opening song "Miyarabi no Inori" (ミヤラビの祈り) and ending theme "Mekagojira wo Yattsukero" (メカゴジラをやっつけろ) were both sung by Berubera Riin (Berbera Lynn), who plays Nami Kunigashira in the movie.
- Released as Godzilla vs. the Bionic Monster in its original 1977 American release by Cinema Shares Distribution (also known as "Downtown Distribution"). A lawsuit by Universal Studios forced a title change to Godzilla vs. Cosmic Monster a short while later (because Universal thought it sounded too close to their TV productions, The Six Million Dollar Man and its spinoff The Bionic Woman, claiming to have owned the word "bionic" back then). Eventually, the film began using the original Godzilla vs. MechaGodzilla title, making it the only Godzilla movie to receive three separate titles in the U.S.
- In 2004, Tristar and Sony Entertainment released on DVD the original international uncut and unedited version of the film, also featuring the original Japanese language track.
- The Anguirus role in the movie was originally written for Baragon, but the suit was in such dire straits after being modified so many times for the Ultraman TV series that the studio chose to use Anguirus as a replacement to fill the role. This could also be interpreted as the reason we see him gain burrowing and leaping abilities, traits that are attributed to Baragon.
- In the scene where the disguised MechaGodzilla fights the real Godzilla, the suit used to portray the disguised MechaGodzilla would be reused at the end of Terror of MechaGodzilla to show Godzilla swimming away.
- Strangely, when the Azumi princess has her vision at the beginning of the film foretelling of a monster coming to destroy mankind, it is portrayed through film stills from Ghidorah, the Three-Headed Monster with flames overlaid on them. King Ghidorah can clearly be seen in the shots, and his roar is used as background sound. However, King Ghidorah does not appear again at any point in the remainder of the film.
- This is the favorite Godzilla film of Godzilla: Final Wars director Ryuhei Kitamura, with his favorite Kaiju being King Caesar.
- This is the last appearance in the Showa series to feature Anguirus. He is absent for 30 years in Toho productions then.
- This film is probably one of, if not the most, bloody Godzilla films. With the death of Eiji Tsuburaya in 1970, the series began to become more graphic in order to compete with rival monster films, like the Gamera series. Such scenes of gore includes the fight between MechaGodzilla (as the Fake Godzilla) and Anguius where MechaGodzilla breaks Anguirus's Jaw in a brutal display,(its might be a referrance to King Kong's move that he did to the V-Rex.) The first fight between Mechagodzilla and Godzilla, when Godzilla falls into the water and blood rises to the surface, and when Mechagodzilla repeatedly fires his laser beam at Godzilla's neck, prompting blood to spray out of the wounds.
- This film marks the second time Godzilla draws strength from lightning; the first was in Ebirah, Horror of the Deep, and the third and final time was in the lightning induced by the atmospheric nuclear explosion from The Return of Godzilla.
- This is the last film directed by Jun Fukuda.
- Released: October 19, 2004
- Aspect Ratio: Widscreen (2.35:1) anamorphic
- Sound: Japanese (2.0), English (2.0)
- Supplements: Trailers for Godzilla: Tokyo S.O.S., The Lost Skeleton of Cadavra, Kaena: The Prophecy, Steamboy
- MPAA Rating: PG for sci-fi monster violence and some language