The story is about Katy, now grown up as a lovely butterfly, and her children, young twin caterpillars names Kiki and Koko, facing off against aliens who came to their forest searching for food which happens to be inhabitants of the forest. With the help of their friends, Katy, Kiki and Koko were able to defeat the alien X and save their forest and its inhabitants. The sequel to "Katy the Caterpillar."