Bagan

Bagan (バガン) is a powerful demon-like kaiju that was planned to be in numerous Godzilla films, but never ended being in one. The only official appearances of Bagan are in the SNES video game, Super Godzilla and in Godzilla Movie Studio Tour.

Appearance
Bagan's original concept was a shape-shifting creature that switched between a dragon form, a fish form, and an ape form, and finally into a totem-like form. Bagan's second concept was a giant bipedal dragon-like creature with two massive spikes on his back, two devil-like horns on his head, and a nasal horn.

Origins
Bagan was an ancient kaiju that was worshiped as a god in ancient China. He was sealed away thousands of years ago, but was awakened in the present day by human activity.

Resurrection of Godzilla
In his first proposed film appearance, Bagan was an ancient Chinese deity that consisted of three separate divine beings: Doragon Reijuu, the sacred dragon beast, Enjin Reijuu, the sacred ape beast, and Mizu Reijuu, the sacred fish beast. Bagan shifted between these three forms and battled the Japanese Self-Defense Forces. Each time Bagan was injured, he quickly regenerated the damage. Godzilla was reawakened by nuclear dumping in the Pacific and traveled to Japan to challenge Bagan. Bagan's forms were all overwhelmed by Godzilla, so he configured himself into a more powerful combination of all three forms: Totem Bagan. Totem Bagan fought Godzilla, but lost his regenerative ability in this form. Godzilla took advantage of this and destroyed Bagan for good. This proposed film was heavily rewritten into what became The Return of Godzilla.

Mothra vs. Bagan
After the cancellation of his first appearance, Bagan was considered as the villain for a standalone Mothra movie. In ancient times, Bagan threatened the human race but was sealed away in China by Mothra. In the present day, human pollution and environmental tampering awakened Bagan, who resumed his war on humanity. Mothra battled Bagan across the globe, but was finally killed by the powerful demon. Mothra's egg hatched and she was reincarnated. The new Mothra traveled to Shanghai to battle Bagan and defeated him. Due to the financial failure of Godzilla vs. Biollante, Toho shelved this movie and produced Godzilla vs. King Ghidorah. Bagan's role in this film would ultimately form the basis of Battra's role in Godzilla vs. Mothra and Death Ghidorah's role in Rebirth of Mothra.

Super Godzilla
Aliens discovered Bagan dormant in China and took him under their control. Using a combination of Godzilla and King Ghidorah's cells, the aliens turned Bagan into a Super Monster. The aliens sent Bagan to battle Godzilla, who had been enhanced by the humans into Super Godzilla. The super-powered Godzilla finally defeated Bagan in a brutal and difficult battle. Bagan roared in defiance and vanished after being defeated, and the aliens left Earth. To date, this game is the only official appearance of Bagan in any media.

Godzilla vs. Bagan
Little information exists about Bagan's final proposed appearance. All that is known is that the film would also feature Godzilla Junior and the Gotengo.

Trivia

 * Bagan has only officially appeared in two Godzilla video games.