Kaynyn Island is populated entirely by dogs, who are ruled by a dog king. Each year the king defends his crown against a challenger; but the current king, Herowag, has corrupted the system. He has instructed his three counsellors always to choose a challenger that he can beat. As Herowag grows older, the challengers grow more decrepit.
A dirty, chubby little poodle named Pippo-Tib is bold or foolish enough to laugh aloud at this; an angry Herowag designates the poodle as the next year's challenger. Things look grim for the little canine; but he finds a way to appeal directly to the dog fairies. Since Herowag is a corrupt tyrant, the dog fairy queen endows the poodle with the strength and wisdom to defeat the king in tests of body and mind. The queen imposes a condition: Herowag must not be killed.
Racing back to the capital on the appointed day of the challenge, Pippo-Tib falls into a lake surrounded by terebinth trees. Their pistashio nuts, falling into the water, have dyed the lake green; and the poodle's white coat has taken on the same coloration by the time he swims across. His appearance creates a sensation when he arrives at the challenge — for there is a prophecy that Herowag can only be defeated by a pea-green-colored opponent.
The two dogs fight. Pippo-Tib, with the fairies' power surging through him, overcomes the old king, dragging him around by his throat; the king begs for mercy. The poodle also wins the battle of wits that follows. Herowag slinks away to a life in retirement; the poodle assumes the crown, to become a better and more just and honorable monarch.
The name of the story's poodle hero, Pippo-Tib, derives from Tippu-Tib, a ruler and military figure in East Africa in the later nineteenth century.
In 1910 Baum adapted this story into a play. The dramatized version was never produced onstage, and has not survived.