I received a copy of this picture book free from the author in exchange for an honest review.
Continuing in the trend of Belches, Burps, and Farts--Oh My! and The Butt Book by Artie Bennet is Poopendous!, a book that tackles an even less "acceptable" subject than gas or butts: excrement. Fictional Professor Pip Poopdeck guides the reader through the book's "putrid and shocking and horrid" subject in hopes of teaching that excrement is more than just the thing that humans hide out of sight in a septic tank (or porta-potty, latrine, etcetera).
There's an "everybody poops" element here as the good Professor talks about how--you guessed it--everyone and almost everything (at least as far as animals a toddler knows about goes) does it, teaching some more unique words for specific types of excrement (guano, dung, flyspecks) and talking about characteristics of some of the more unusual types of animal droppings (wombats cubes, wet bird poop). And once that's out of the way, the book moves on to discussing--in rhyme, of course--how dung is used around the world and in the animal kingdom. It talks about dung beetles (how could it not?) and fertilizer, endozoochory and territorial marking via scat, and how the Mongols and Masai use dung in their construction, as well as some of humanity's sillier uses for poop.
Essentially, it's a frank but funny look at poop that attempts to utilize most children's love of potty humor as an opportunity to learn. I'd say it does a good job of normalizing the subject and manages to avoid making it seem too gross, though I wouldn't be surprised to hear that some parents/teachers comfortable with Belches, Burps, and Farts--Oh My! and The Butt Book might still have some trouble with the idea of reading an entire book about poop.
On the other hand, the three books come together to make an amusing trilogy of educational potty humor, each revolving around the rear in some capacity. I definitely recommend checking out all of them if you think they're the type of thing you and your children/students might be interested in (or you have already read/enjoyed one of them); personally, I'd start with Butt before moving on to Belches and then Poop, but that's just me.
I'm going to be on the lookout for more humorous edutainment books like this in the future, so if you have any recommendations, feel free to let me know below!