I wanna be honest and start off saying that I never read any of the captain underpants books its just not my cup of tea, but making a movie based off the books that are like 20 or 30 years old since the first issue was publish, is both a good and bad idea.

And reason is simple. Making a movie based off either the books or comics meaning you have to follow every source material, the characters and their development throughout each issue, the details, points, plots, etc. And try to cram as much in there as possible.

For example ; the harry potter movies. They follow much of the books as possibly BUT they cut most of the book out of the movie to prevent droning out the movie which result of boring the audience. All is going well until someone in the production decided to cut the final movie, the deathly hollows, into 2 parts. And guess what? The audience (on my end) are not to please with that at all.

We're watching a movie, not a fucking MLP episode. (Yes i said that just the first episode alone is seperated into 2 parts)

So morale to the story is this; if you want to make a movie based off of books or comics, follow the books/comics as much as possible and try to cram it all into one movie. Also we also don't mind a few changes in the movie as well but do not try to alternate the which was the result of said changes of the movie.

I think Captain Underpants will do well if they make it a series. For one the books are far shorter then the Harry Potter Novels and they have as much action as they do dialogue. Plus there's plenty of comedy in the books. As I said my only problem is really with George and Harold's voices. They really don't match.

Mind enlighting me how comedic the novel versions of the characters then the ones in the movie?

No I was talking about Captain Underpants with the comedy not Harry Potter.

Oh! Duh...

Meh, we all make mistakes.