A song made in 1944 in southeast Asia mentioned about Seamons and Seagorath. Then one night, a ship known as the Poseidon was suddenly attacked by Seamons. After sinking the ship, Seamons attacked two fishermen, MAT finally believed the existence of Seamons.

Later, on the island of Hachijōjima, Seamons rose from the ocean and attacked a refinery. MAT arrived to slow Seamons down, surrounding the monster in a wall of fire with their weapons. Feeling threatened, Seamons howled out to her mate. Seagorath heard the call and using his own weather control powers, Seagorath created a tsunami hundreds of feet tall and directed it towards Japan. Luckily, Ultraman Jack arrived, creating the Ultra Barrier and successfully repelled the tsunami back, subduing Seagorath by dragging him underwater, but losing most of his own energy in the process. With Ultraman Jack weakened, Seamons easily fought Jack to a standstill, forcing Jack to leave while Seamons continued her rampage.