The Cat in the Hat Knows a Lot About That! has 40 half-hour episodes. PBS Kids renewed it for a second season of 20 episodes which premiered on September 10, 2012. A 20 episode third season is currently in development. Each episode features The Cat in the Hat (voiced by Martin Short), who leads neighbours Nick and Sally, the Fish, and Thing One and Thing Two on a variety of adventures in his "Thinga-ma-jigger", a Seussian contraption that can sprout wings, pontoons, booster rockets, change size, and do just about anything else necessary to further the adventure. The adventures are prompted by a question posed by either Nick or Sally
The Cat in the Hat "My Hassle With the First Grade Language", he also told a story of the "three excruciatingly painful weeks" in which he worked on a story about a King Cat and a Queen Cat. However, "queen" was not on the word list, nor did his first grade nephew, Norval, recognize it. So Geisel returned to the work but could then think only of words that started with the letter "q", which did not appear in any word on the list. He then had a similar fascination with the letter "z", which also did not appear in any word on the list.