PERSIFLAGE AND BADINAGE
Here's one for the history books. During Walt Kelly's sojourn at the Disney Studios in the 1930s, he and others on staff used to circulate among themselves sketches and caricatures, poking fun at each other. Some of these spontaneous generations were a little off-color, but Ward Kimball (one of Disney’s “nine old men”) says Kelly avoided such forays into comedic pornography: “He stuck with very innocent, basic humor” (quoted in Hermes Press’ Walt Kelly: The Life and Art of the Creator of Pogo). But Kelly did allude in print to an old shady story at least once that I know of.
The daily strip for September 26, 1952 (the middle one in the array posted near here), echoes an ancient slightly racist joke about an old raggedy black man who fell asleep under a tree in the woods.
While he slept, a black snake crawled up under his tattered trouser leg. The snake kept on crawling up the pants leg, and when it got to a hole near the man's crotch, it emerged and raised up in front of the sleeping man's face, whereupon the man awoke. Staring sleepily at the snake weaving in front of him, he muttered: "My sakes! I knowed yo' was black, and I knowed yo' was long, but where did yo' get those baby blue eyes!"
Kelly was reputed to be squeamish about rude jokes of this kind, but it would appear that he repeated almost exactly this one’s punchline, rude or not. And he may have done such jokes more than once, but this is the only instance I know of. In this case, I suspect that what Kelly found amusing was the black man’s language, not anything else in the situation.
Assuming that Kelly deliberately evoked memories of this old chestnut, we must also realize that he was not unique among his cartooning colleagues. Cartoonists were widely regarded by syndicate and newspaper editors as adolescent pranksters constantly finding ways to insert scatological references or sexual innuendoes into their strips, sneaking them by their editors' scrupulous eyes into the unsuspecting world of newspaper readers beyond. There, certain readers would recognize the signs and symbols and potents; and they would laugh uproariously in appreciation of the cartoonist's daring and cleverness. So I've heard. (Milton Caniff told me; his Hotshot Charlie in Terry and the Pirates was an instance of this nefarious practice although Caniff never finished the allusion by quoting the punchline.)
Al Capp became notorious for such practices in his Li’l Abner, and then Joe Palooka's Ham Fisher blew the whistle on him. You can find the whole story in the Usual Place (RCHarvey.com), in Harv’s Hindsight for January 2013, “Hubris and Chutzpah.”