According to the book, the 13-storey treehouse has "a bowling alley, a see-through swimming pool, a tank full of man-eating sharks, a secret underground laboratory, a vegetable vaporizer and a marshmallow machine that shoots marshmallows into your mouths when it sees that you are hungry".

[6] The book begins with the narrator and fictional depiction of the author, Andy Griffiths, giving an introduction to himself, his friend and illustrator Terry Denton, and their treehouse.

Andy wakes up one morning, and on his way to getting breakfast, he meets Terry, painting a white cat yellow to turn it into a canary, or a "catnary".

Andy and Terry are then greeted by their animal-loving friend Jill, who wants to find her pet cat, Silky.

Right after Jill leaves, Andy and Terry receive a call via a 3D video phone by their publisher, Mr Big Nose, who is upset that the duo is behind schedule.

But before anyone can say more, Terry gets distracted by television as his favorite show, Barky the Barking Dog, is airing.

He overhears the love conversation from the bath door, which ends in Terry kissing Mermaidia.

Once Terry runs off, Andy enters the bathroom and finds out that Mermaidia was a sea monster in disguise.

When Andy and Terry began to write their book, a giant gorilla started shaking the tree yelling, “BANANA!” Then a chauffeur arrives, informing Terry has won the Barky the Barking Dog drawing competition and gets to meet Barky.

They write the events up and with the help of Jill in a Santa-like sleigh, get their book to Mr Big Nose for it to be published.

The book has spawned a series of sequels, each of them adding 13 stories and new characters, as well as continuing the use of meta and absurdist humor.