This one is featuring one of Z.'s favorite characters, The Pigeon:
You can't quite make it out, but the book The Pigeon is reading is titled, "How to Drive a Bus," which is hilarious if you've ever read, "Don't Let the Pigeon Drive the Bus" by Mo Willems. (Or, perhaps, if you've ever heard the title, "Don't Let the Pigeon Drive the Bus," and put two and two together!)
I also like the placement of this poster in nonfiction. The Pigeon is advertising how-to books!