POGO is one of the classic strips, it ran from 1948 to 1975 (although Walt Kelly did earlier comics with similar characters). It's about a bunch of animals interacting in the Okefenokee Swamp. A lot of the humor comes from the way they can speak and wear clothes, use typewriters and so forth, but really don't understand what they're doing. There's a lot of satire and social commentary just under the surface. Later on, the strip got more political as Pogo dealt the various world leaders in animal form, as well as things like the Jack Acid Society. I prefer the earlier stuff, I think it's more whimsical and touching but a lot of people like the political satire better.
POGO has been reprinted in various collections over the years, and I find reprints in used book stores often. It's worth checking out if you think it looks interesting. The art alone is classic; notice in the first panel here that Pogo only has managed to get one slipper on when answering the door.