18 books in series

Treehouse

Treehouse is a 19-book series with 18 released primary works first released in 2001 with contributions by Andy Griffiths, Terry Denton, and Richard Tulloch.

Terry's Dumb Dot Story: A Treehouse Tale
The 13-Storey Treehouse
The 26-Storey Treehouse
The 39-Storey Treehouse
The 52-Storey Treehouse
The 65-Storey Treehouse
The 78-Storey Treehouse
The 91-Storey Treehouse
The 104-Storey Treehouse
The 117-Storey Treehouse
The 130-Story Treehouse
The 143-Story Treehouse: Camping Trip Chaos!
The 156-Storey Treehouse
The 169-Storey Treehouse: the bestselling series
Ten Unlucky Pirates: A Little Treehouse Story 1
Tales from the Treehouse
The 13-Storey Treehouse: A Play for Young Audiences
Barky the Barking Dog: A Little Treehouse Story 2
The Treehouse Joke Book