While on a final mission, Ricky, aka the superhero dressed as a rat, Ratfist, is bitten by a rat and actually transformed into one. Now, to get a cure, he joins forces with his disembodied tail, his pet rat Milt, and an alien named Space Tiki to save himself and his relationship from corporate and political greed.

In this exciting sequel to Escape from the Lizzarks, Herk is happy to have a new family and a new place to call home. But when the Lizzarks make an all-out assault on Amphibopolis using a giant monster, Herk must seek the help of the megasloth to save the city and his adopted family. Meanwhile, Sissy, Herk's sister, discovers the dark truth about their long-lost brother Zerk--and truth that will affect Herk and the future of all Nnewts.--