The novel begins with the introduction of the hero, Chauntecleer, a rooster in command of a company of hens, and the land surrounding his coop.
The novel's initial chapters define several important characters as well as the origins of the main antagonists in the book, Wyrm and Cockatrice.
While Chauntecleer spends his days dealing with a rogue rat that has invaded his coop, and trying to become accustomed to a newcomer, Mundo Cani, a depressed dog that is always crying out in anguish, the reader is shown another country from across the river.
He becomes an evil tyrant and begins to rape all of the laying hens under his rule, in order to give birth to an army of wicked basilisks; poisonous snakes that he uses to crush any opposers to his will (Toad is killed with them) and destroy the country.
A few of the animals manage to escape the land, and flee into Chauntecleer's kingdom, where they live happily for a while, trying to forget the nightmares of their past.
The Dun Cow, one of God's messengers, brings an enigmatic riddle to him about the ways he can defeat the trio of evils: Cockatrice, his basilisk army, and Wyrm himself.
During the day he tries to find happiness, but everyone is immediately struck with unbearable sorrow when the rooster's three sons are found lying dead by the river.
The same egg-eating rat that Chauntecleer drove away is discovered dying, holding part of a venomous serpent (a basilisk) in his mouth.
Before long there is a surprise attack on a goofy wild turkey named Thuringer, who dies from a basilisk's bite.
Unfortunately Cockatrice has not yet been dealt with, so the brave Chauntecleer dons a pair of war spurs (the weapon of choice for a bipedal bird) and goes onto the blood-soaked battlefield to confront his enemy.
Chauntecleer faints from weakness, and is brought back to the coop, which has by now been transformed into a fortress, where they try to resuscitate their fallen, but victorious, hero.
The animals all find it difficult to fit back into their normal lives, especially Chauntecleer, who after bottling his emotions for a while, breaks down in front of his wife.
He cries out in pain, knowing that the last thing he said to Mundo Cani before his great sacrifice, were words of scorn and hatred.