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 Grinch Grinches the Cat in the Hat died a few months before this special had aired. Boris Karloff, the original voice of the Grinch, had died in 1969), while Mason Adams took over voicing the Cat in the Hat from the late Allan Sherman, who died in 1973. Since Friz Freleng was absent from production on "The Pink Panther" special "" due to his departure from DePatie–Freleng Enterprises to return to Warner Bros. Animation, this was the only other fully animated DFE production to be made by Marvel Productions and one of the last DFE cartoons Freleng was involved in. The special was first released on VHS