As the story opens, it is too rainy and too cold to play outside, so two kids named Sally and David sit bored and look out the window. Their mother announces that she is ready to depart, then tells them to have fun and says she'll return at 3:30 sharp. While their mother is out, they have no other choice but to think of something to do. The mysterious Cat in the Hat suddenly enters with a bump and fools around a bit. The family goldfish named "Karlos K. Krinklebein" orders him to leave, but instead the Cat plays a game which he calls "Up, Up, Up, With a Fish", placing the fishbowl on top of a stack of bubbles. The children notice that the Cat is making the house a little untidy, and Conrad recalls their mother's projected return at 3:30. Noting their objections, the Cat bows to the voice of the majority and dejectedly states that he is going to Siberia, Russia. Immediately after leaving, however, the Cat bursts back in claiming that his "moss-covered three-handled family gredunza" has been stolen. The Cat accuses Karlos of being the thief, and sings a ballad about the loss of his treasured keepsake. The Cat then leads the kids on a search for the missing gredunza using his method of, in which random numbers and letters are drawn anywhere the gredunza should be to mark that they have already checked there. This makes a mess of everything, and Karlos once again orders the Cat to leave. Ostensibly to gain sympathy, the Cat sings a pessimistic song to convey his low self-esteem, then puts Karlos to sleep by singing a lullaby. Having made a miraculous recovery from his bout of depression, the Cat brings out Thing One and Thing Two to aid in the search for the gredunza, singing to the kids that they can find, but instead of being productive, the Things play a variety of sports using Karlos' fishbowl, noting that every house they visit has a pessimistic fish “whose only one wish is to flatten the fun.” Furious, Karlos accuses the Cat of not being a real cat, and his hat of not being a real hat. However, the Cat indignantly asserts his legitimacy by singing his name in several languages. The tune becomes so catchy that everyone, even Karlos, joins in and contributes, telling the Cat that in Russian he is a "chapka in a shlyapa". As the song ends, a car horn is heard in the distance. Karlos spots the kids' mother on her way home. The Things get back into their box and disappear, then the Cat exits immediately after. With the house an extreme mess, the kids wonder how they'll clean the house in time. The Cat quickly returns, using a motorized vehicle to tidy things up in a jiffy. After cleaning the house, he departs, hinting that he may return someday. Just as he departs through the back door, the mother walks in through the front door; she asks the kids how their day was, and then tells them that she just saw a cat in a hat "going down the street with a moss-covered three-handled family gredunza". The exact identity of the object has never been revealed, but this indicates that the gredunza was never really lost, and the Cat simply wanted an excuse to have more fun. Sally and David look out the window much as they did at the beginning of the special, and watch as the Cat walks off to his next adventure.
The production began at Chuck Jones' MGM Animation Studio in the late 1960s after the studio had finished The Phantom Tollbooth and another Dr. Seuss special, Horton Hears a Who!. After MGM stopped animation production and closed down its animation department for good in 1970, production was moved to DePatie–Freleng Enterprises, which was run by Jones' fellow Warner Bros. Cartoons alumnus Friz Freleng and WB's last original production executive David DePatie. Although Chuck Jones and his staff were retained by DePatie–Freleng in the production of the special, Jones left the studio and did not work on any other Seuss projects after The Cat in the Hat. Other staff members that have worked with Jones such as Dean Elliott and Maurice Noble eventually stopped working on Seuss projects also. DePatie and Freleng were credited together as executive producers, while Jones was credited as producer with Seuss. For the next three Dr. Seuss animation specials, Freleng and Seuss were credited as producers, although separately. DePatie–Freleng animated a new Cat in the Hat Productions logo for this special, which would be used in the next three specials. The pace and rhyming sequences of several of the songs led many to believe that they were composed by Sherman, since they closely resemble his earlier song parodies, however only Seuss is credited.
Differences from the book
The plot of the special differs significantly from the original book. Among the many deviations, the sequence in the book where the Cat balances all sorts of objects while standing on a ball, only to overdo it and come crashing down, is left out. The closest equivalent is the fishbowl and bubbles sequences. Also differing is the role of Thing 1 and Thing 2; in the original book, they were simply things the Cat brought along to demonstrate fun, but in this special, they are commissioned to help find the cat's "moss-covered three-handled family gredunza". The vocabulary used in the special is also on a higher level than the book's, though still in Seuss' trademark rhyme.
Although the original book's sequel The Cat in the Hat Comes Back did not receive an animated adaptation, the character went on to appear in several more Dr. Seuss specials. In 1973, there came Dr. Seuss on the Loose, where Sherman reprised his role as The Cat in the Hat. Here, The Cat in the Hat appeared in bridging sequences where he introduced animated adaptations of three other Dr. Seuss stories: The Sneetches, The Zax and Green Eggs and Ham. In 1982's The Grinch Grinches the Cat in the Hat, the character, now voiced by Mason Adams, meets the title character of How the Grinch Stole Christmas! and sets out to reform his new green adversary. In 1995, the Cat appeared again, this time with the voice of Henry Gibson, to narrate Daisy-Head Mayzie, a special based on a posthumously published Dr. Seuss book. In 1996, a puppet version of the Cat starred in The Wubbulous World of Dr. Seuss, where he was voiced by Bruce Lanoil and Martin P. Robinson. The Cat in the Hat Knows a Lot About That!, an educational animated series based on the Random House Library series, premiered in September 2010; the Cat is voiced by Martin Short.
