Monsters

With the collapse of the government after the Second World War, Americans have learned to live without help or interference from police, lawyers and bureaucrats. In this simple and happy world lives an eleven-year-old boy who wants to be a scientist. Unfortunately, he's grounded for taking his friends into outer space in his spaceship without asking first. Now there's nothing to do to escape boredom but make monsters. He starts with a strange fungus he finds at school.
Unfortunately his specimen becomes a little too hard to handle when it grows into a giant and learns to move. Before he can destroy it, the thing makes its escape into the neighbors' pond. Making a submarine to go after it doesn't quite work out, though, when the sub becomes a snack for a giant octopus.
No matter, for the scientist and his friends have more pressing concerns than a fungus monster and a giant octopus. By mixing frog DNA with a chicken egg they've accidentally created a dinosaur which threatens the entire county.