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 from which he releases two identical creatures with blue hair and red suits called Thing One and Thing Two. The Things cause more trouble, such as flying kites in the house, knocking pictures off the wall and picking up the children's mother's new polka-dotted gown. All this comes to an end when the fish spots the children's mother out the window. In response, Sally's brother catches the Things in a net, and the Cat, apparently ashamed, stores them back in the big red box. He takes it out the front door as the fish and the children survey the mess