Once upon a time, there was an alien invasion. The aliens were big and green, and they had big heads and big eyes. They came to Earth in their spaceships, and they started to destroy everything. The humans fought back, but they were no match for the aliens. The aliens were about to win the war, when a young boy named Billy had an idea. Billy knew that the aliens were afraid of cats, so he gathered all the cats in the world and led them into battle. The cats attacked the aliens, and the aliens were so scared that they ran away. The humans were victorious, and they were all grateful to Billy for saving the day.