Pogo (the comic strip) was interesting because it combined art, humor, and social awareness. Like Alice in Wonderland, it's perfectly enjoyable to little kids, but more is going on. For instance, a bloodthirsty hillbilly wildcat representing Senator Joe McCarthy appeared several times, browbeating the swamp-dwellers with paranoid speeches — at a time when explicitly criticising McCarthy was practially treason.
Harry Truman, the young Richard Nixon, and various generals and captains of industry, specific and symbolic, also appeard in animal form, usually trying to sell something dangerous for a bad price. I don't recall a single complimentary caricature; the heroes of the strip were all ordinary animal folk.
The comic strip was probably the most mature running commentary on the early Cold War, and even caught on to the danger of environmental pollution before it was trendy. (A modern equivalent is Bloom County, which also combined politics into nonsense humor — witness Bill the Gates and Bill the Cat's defection.)
The art was generally very fine, though often reproduced badly. Calvin and Hobbes, Mutts, and Sinfest are clearly influenced by Walt Kelly's simple, moderately stylized, from-the-side look. Its appeal to me is not in panoramic vistas or thrilling action (in a 2"·6" strip?) but in the little details: the eyebrows and ekphrasis.
Pogo himself was a sympathetic and unassuming possum with a sense of romance. He had a bit of the Zen monk in him, and enjoyed himself without ever getting too worked up about anything. Albert Alligator, Pogo's best friend, was excitible, gluttonous, and, when he could manage it, deboinaire. (I think my favorite sequence was Pogo's adventure in his stomach — the candle, the ladder, the sound effects ... genius.) Churchy la Femme, a mud-turtle and gentleman, was sensitive, neurotic, and given to conspiracy theories. ("Egads! Friday the thriteenth falls on Wednesday the twenty-third!"). Miz Beaver, a self-righteous single mother, smoked a corncob pipe and set people on the straight-and-narrow at every chance. The Deacon, a blind mole, was — well, just go buy one of the books.
And there's the problem. Pogo is out of print except for expensive artsy revival stuff — Pogo as history. (The publication date is printed (in Helvetica) by every strip, and you just know it's only ever going to be read by grad students looking for literary symbolism in every speech bubble.) It's good stuff, and it deserves a good printing for people who actually like it.