Andy Griffiths

Adding new stories to their treehouse to accommodate a soap-bubble blaster, a toilet paper factory, and an extraterrestrial observation center, Andy, Terry, and Jill are abducted by a giant flying eyeball for an intergalactic space adventure.

Visiting the new camping ground level for some R&R, Andy and Terry find things not going as planned when the campfire stories are a little too spooky and their fellow campers start mysteriously disappearing.

For all the books they have written, Andy is the narrator and Terry is the illustrator, but when Terry tries to narrate too, the story goes out of control and they must evade the Story Police, who want to arrest them for crimes against storytelling.

Andy and Terry live in a treehouse. But it's not just any old treehouse, it's the most amazing treehouse in the world!
This treehouse has thirteen stories, a bowling alley, a see-through swimming pool, a secret underground laboratory, and a marshmallow machine that follows you around and automatically shoots marshmallows into your mouth whenever you are hungry.
Life would be perfect for Andy and Terry if it wasn't for the fact that they

...

Continuing their efforts in the ever-expanding treehouse, Andy and Terry tackle the mystery of their missing publisher, Mr. Bignose, whose disappearance has made completing their next book rather difficult.

"It's the night before Christmas but Andy and Terry aren't ready yet! They haven't written their letters to Santa, they haven't sung any carols or hung their stockings, and now Mr. Big Nose wants their next book done by tomorrow. When Santa Claus's sleigh crash-lands in the treehouse, the reindeer become tangled in the branches and Santa falls into the cloning machine. With dozens of Santas running around and no way to tell which one's the real one,...

Andy and Terry travel through time trying to save their treehouse from highly talented, angry ants and Inspector Bubblewrap the building inspector while rushing to meet their publisher's deadline.

"Andy and Terry live in a 169-story treehouse. (It used to be a 156-story treehouse, but they've added 13 more stories.) It now has a kangaroo-riding range, a whatever-weather-you-want dome and a hall of funhouse mirrors--the perfect place to hide from the truancy officer who is trying to catch them and make them go to school! Unfortunately, the hall of funhouse mirrors is also the place where their evil trouble-making twins, Anti-Andy, Terrible Terry...