DaBoom

Peter is warned by a Giant Chicken that the world is going to end at midnight. So he traps his entire family in the basement, where they actually do survive a nuclear holocaust. In order to survive in the new world, the Griffin's travel to a Natick, where they believe there could be a twinky factory. When they get their, they realize they were correct, and start a new town called "New Quahog" with Peter as the mayor. However, after everyone realizes Peter is a lousy Mayor, they kick the Griffin's out of town. Meanwhile, on the way there, Stewie falls in some radioactive waste, which mutates him into an octopus creature.