The Cat in the Hat (film) with some critics, stating that it should have instead been rated PG-13 in relation to its high amount of adult content. Leonard Maltin in his Movie Guide gave it one and a half stars out of four saying that the "Brightly colored adaptation of the beloved rhyming book for young children is a betrayal of everything Dr. Seuss ever stood for, injecting potty humor and adult (wink-wink) jokes into a mixture of heavy-handed slapstick and silliness." Maltin also said that the film's official title which included "Dr. Seuss' The Cat in the Hat" was "an official insult". Conversely, "Variety" praised
The Cat in the Hat for the series, including "The Cat in the Hat Comes Back" (1958), "Green Eggs and Ham" (1960), "Hop on Pop" (1963), and "Fox in Socks" (1965). He initially used word lists of limited vocabularies to create these books, as he had with "The Cat in the Hat", but moved away from the lists as he came to believe "that a child could learn any amount of words if fed them slowly and if the books were amply illustrated". Other authors also contributed notable books to the series, including "A Fly Went By" (1958), "Sam and the Firefly" (1958), "Go, Dog.