Henry Huggins makes a deal with his father--if Henry can keep his dog Ribsy out of trouble for a month, he can go fishing with his father. Ribsy does his best to make Henry lose the deal.
Henry Huggins picks up a stray dog, names him Ribsy and sets out on numerous adventures with him, including breeding hundreds of fish and collecting over a thousand worms.
Henry Huggins gets carried away with his own ambitions when he longs for a paper route of his own, and gets some unexpected help from the irrespressible and inescapable Ramona Quimby.