Viviane Schwarz is the author and illustrator of one of my all-time favorite picture books, Timothy and the Strong Pajamas, a tale about a pair of beloved ripped pajamas and some special repairs that mom makes on them. With her cats books, we get a bit more play and a little less text, but a big dose of creativity and paper engineering in between the covers. While their illustrative style is different, Schwarz's books remind me of the wonderful Emily Gravett's works, espeically Meerkat Mail and Spells.
With her cats books, Schwarz's cats talk to the reader. Really, I could go on, but it would be much better if you watch this video of There are Cats in This Book being read out loud.