Inside the Villains by Clotilde Perrin was published in September 2018 in the United States and the UK in English translation of the original French edition of À l'intérieur des méchants published in 2016. I got to peruse it in a small independent bookstore and was intrigued by it. There are not many pages, just three spreads devoted to the Wolf, Giant, and Witch. But this is an interactive book where you lift flaps, explore the text, and find surprises. It's not technically a pop-up book but it fits in the general category that way.
The book has a very French sensibility and some elements may be deemed too disturbing for some kids by some parents while others will adore it. There are kids in my life I would show this to without qualms and others will be waiting a few years.
The grotesque is accepted just a little bit more for French kids in their published literature in my experience. After all, France still embraces Donkeyskin, too, yay for them. From what I can see from the online images of the French version, the English translation is pretty literal of the original. But even the French reader reviews have a few warnings of the book being not suitable for the youngest kids. So I'm not trying to stereotype too much here either. Let's just say I was not surprised to see that this was a book in translation after my experiences with international fairy tale publishing...
An extraordinary lift-the-flaps book that reveals the secrets of the most famous fairy-tale villains--the giant, the wolf and the witch--with interactive flaps, a twist on well-known tales, and personality cards for each villain. Lift the flaps to see the diabolical thoughts inside the villains' heads, what hides beneath their disguises, or the victims of their last meals (now comfortably settled inside their stomachs!).
Read all about each villain on their personality card, which shows strengths and weaknesses, pastimes, physical characteristics, their best meal and--of course--their favorite books.
And if the wolf bites your fingers while you're reading, you can always pull his tail...
In France, there is also the companion book, A l'intérieur des gentils published in 2017. It has not been translated into English. See a few pages from it at Seuil Jeunesse.
For online viewing, a video is a better way to comprehend the book. So I am sharing this video from Gecko Press which shows the French text and the book "in action":