Great series for kids 5 and up. Lots if great imagery and crazy ideas. We read them all the time and already own quite a few. I believe there are at least 10 in the series .
Blurb (from website)
With lots of laughs at every level, Andy Griffiths and Terry Denton’s Treehouse series follow the adventures of best friends Andy and Terry who live in an ever-expanding treehouse.
(Andy writes the words and Terry draws the pictures) .. in each book they are working towards writing a book but a crazy adventure happens along the way.