The Giant Manta Ray was mutated from the extreme heat of a volcanic explosion in the ocean. When it noticed the Calico, it tried to attack, but Godzilla was summoned. The Giant Manta Ray shot an energy bolt at Godzilla, but Godzilla wasn't affected and punched the Giant Manta Ray, which sent it back to its reef.
After all the ocean creatures were put in the reef, the Giant Manta Ray flew out of the water and started fighting Godzilla again. Godzilla squeezed the Giant Manta Ray and threw it back to the reef. While it was sinking, Godzilla threw an iceberg at the reef which dropped the temperature and made all the animals their normal sizes again.
The Giant Manta Ray can fire a bolt of energy from its tail.
The Giant Manta Ray can fly and swim underwater.