Seuss has stated that the titular character Yertle represented Adolf Hitler, with Yertle's despotic rule of the pond and takeover of the surrounding area parallel to Hitler's regime in Germany and invasion of various parts of Europe. In 2003, reporter John J. Miller also compared Yertle to the former Iraqi president Saddam Hussein, saying that "[i]ts final lines apply as much to Saddam Hussein as they once did to the European fascists".
Though Seuss made a point of not beginning the writing of his stories with a moral in mind, stating that "kids can see a moral coming a mile off", he was not against writing about issues; he said "there's an inherent moral in any story" and remarked that he was "subversive as hell". "Yertle the Turtle" has variously been described as "autocratic rule overturned", "a reaction against the fascism of World War II", and "subversive of authoritarian rule".
The last lines of "Yertle the Turtle" read: "And turtles, of course ... all the turtles are free / As turtles, and maybe, all creatures should be." When questioned about why he wrote "maybe" rather than "surely", Seuss replied that he didn't want to sound "didactic or like a preacher on a platform", and that he wanted the reader "to say 'surely' in their minds instead of my having to say it."
The use of the word "burp"—"plain little Mack did a plain little thing. He burped!"—was also an issue before publication. According to Seuss, the publishers at Random House, including the president, had to meet to decide whether or not they could use "burp" because "nobody had ever burped before on the pages of a children's book". However, despite the publishers' initial worries, it eventually proved to be a hit—in 2001, Publishers Weekly reported that it had sold over a million copies in the United States and was 125th on the list of all-time best-selling children's books.