Satkuma

Satkuma (サクマ, lit. Sakuma) is a giant bat-kaiju created by Max Carroll that first fought Godzilla in the fan film Godzilla 1980.

Originating as a mutated bat born from plasma energy in 1975, Satkuma first attacked humanity in 1980, causing several airliner disasters over the nation of Japan. Satkuma was first encountered by the J.S.D.F., but the monster decimated their forces and made a bee-line for San Francisco.

At the same time, a second Godzilla also emerged from Japan, having already attacked Honolulu. The U.S. and Japanese governments determine that the 2 monsters were on a collision course for San Fransisco. The monsters met in the heart of the city, where they engaged in a vicious final battle, before Godzilla finally defeated the exhausted Satkuma with the kiss of death.

Godzilla 1980
In the year 1975, at a power-plant in northern Japan that specializes with plasma radiation. Suddenly, one of the reactors has a breach, and a meltdown ensues. A rare species of bat, native to Japan, is flying nearby when it wanders towards the radiation-filled plant, and it gets bombarded with massive amounts of plasma radiation, mutating it.

5 years later, in 1980, strange events begin to occur. A series of unexplainable plane crashes occur in the country, and the presence of plasma radiation causes the government to scratch their heads in disbelief. Out of desperation, the government brings in American radiologist/paleontologist, Chris Jackson, to investigate both the shipwrecks and plane crashes. Jackson then determines that the radioactivity from the planes can be traced back to the abandoned plasma-plant in northern Japan. There, Chris and the J.S.D.F. discover a massive, winged creature resting in the remnants of the plant. Suddenly, the monster awakens and attacks the J.S.D.F., killing most of the soldiers, with only Chris surviving, and going on a rampage across Hokkaido.

The Japanese government mobilizes in the city and does battle with the bat, only to be crushed by it's firey breath. One of the soldiers then dubs the bat "Satkuma" based on an ancient Japanese legend about a monstrous bat that fed on the souls of the damned.

At the same time, a new Godzilla emerges off the coast of Hawaii, attacking the city of Honolulu before returning to the sea.

Afterwards, the Japanese and U.S. governments conclude that both Godzilla and Satkuma are on a collision course off for San Francisco. With this knowledge in mind, the American and Japanese governments join forces to destroy the kaiju, by using a nuclear warhead as bait.

Satkuma arrives in the city first, wreaking havoc on the poorer district of the city. Godzilla arrives, and Miki secretly takes control of the King of the Monsters, due to her belief that humanity should not interfere with the affairs of monsters, because humanity cannot destroy them no matter how hard it tries. She then secretly mumbles to herself "let them fight" before Godzilla begins heading for his vampiric enemy. The mutant dinosaur approaches Satkuma and bellows a roar of challenge. Satkuma then takes flight and the two go at it. Godzilla pulls Satkuma out of the sky and begins pounding on him, using his sheer weight to do so. However, Satkuma uses his plasma fire breath, but Godzilla counters with his atomic breath, causing a short beam lock that ends with the two being pushed back several meters after the resulting explosion. Godzilla wrestles with Satkuma some more and pulverizes him into a skyscraper. Satkuma then suddenly gains the upper hand when he kicks Godzilla and starts to use hurricane winds against him, causing the nuclear king to fall over. Godzilla then continues to use his radioactive fire to weaken Satkuma. However, the monstrous rodent spawns a literal tsunami of plasma energy that decimates half of the city, but Godzilla survives. Eventually, after a long battle, Godzilla drags the weakened Satkuma out to sea, and kills him with the kiss of death.

Trivia

 * Satkuma was partially inspired by the Heisei incarnation of the Gamera kaiju Gyaos, due to their similar body structures.
 * In addition, the monster was also inspired by the Giant Bat, a monster that appeared in Godzilla: The Series, an animated continuation of the 1998 Godzilla film.