Mutated from a strange pink gas, it terrorized the Calico Crew and a miniature Godzilla, who had been shrunk by the same gas. However, Godzilla was soon restored to his original height, and the King of the Monsters proceeded to do battle against the enormous insect. Godzilla emerged as the victor of the battle.
The Giant Fly has no known powers apart from the typical abilities a normal fly possesses. However it is highly intelligent, and pursues the Calico crew out of revenge for trying to swat it when it was smaller.