A revered God of the undersea kingdom of Mu. Where as most civilizations often worshiped an unseen deity or spiritual higher power, the undersea people choose to follow a more tangible entity.
While the Mu people once lived above the surface, 12,000 years ago they struggled with the hardship of having their land sink into the Pacific Ocean. The dragon-like Manda, though, was perfectly adapted to the water. Face-to-face with the giant serpent, the Mu shaped their society around the beast. From ritualistic dances to rich art created in his honor, their world revolved around Manda. In return for their adoration, Manda seemed to harbor a symbiotic relationship with them. Living out of the water, deep inside their kingdom, the beast would act as a deterrent to invaders. To honor the beast, sacrifices would be made to appease the creature's hunger.
When the undersea people began to prepare for war, the dragon-like kaiju was used for inspiration. Outfitting their Mu Submarine, the race built a powerful ray gun, shaping the cannon after Manda. After the Mu had launched their war against humanity, their agents managed to kidnap photographer Susumu Hatanaka and Makoto Jinguji, the daughter of the Gotengo's captain. The Mu wisely deduced the Gotengo battleship as a threat to their invasion. Consequently, unless given control over the ship, the queen of the Mu threatened that the pair would be sacrificed to Manda.
Eventually the two managed to not only escape their jail cell, though, but also kidnap the queen in the process. Preparing to escape in the high pressure resistant suits of the Mu, the queen triggered a detonation. The blast led Manda to the ocean waters. The creature then created a natural blockade, threatening those who wanted to escape in the high pressure suits. The dragon-like monster wasn't the only thing in the waters, though...
A short distance away, the Gotengo, having followed a Mu Submarine earlier, watched the scene play out. Looking to distract Manda, the ship unleashed a series of torpedoes that detonated around the monster. Filling the waters with a thick, black substance, Manda was unable to see. Realizing their fortune, he humans swam toward the Gotengo in their suits. Once aboard, the drill ship surfaced, the Mu queen aboard against her will. However, it didn't take long for the ship's captain, Hachiro Jinguji, to have a talk with the queen and come to a realization: Mu had to be destroyed. If not, the species would strike again. Realizing what they had to do, the Gotengo plunged back into the water.
Once below the surface, the battleship quickly came into contact with Manda. Combined with the hate, cruelty, and malice of a warlord, the giant serpent attacked the giant submarine without hesitation. Relentless and filled with animal lust, he coiled his scaly mass around the reinforced hull. Constricting like some demonic python, he tried to seal the humans' fates. However, the Gotengo was not defenseless and released from the hull a high tension current. The god was struck with pain, and retreated to the depths, where it was followed and frozen by the Gotengo's Zero Cannon. The incident marked the end of the Mu's revered God, as the battleship drilled further into the kingdom.