One of the reasons I enjoy the comic strip "Pearls Before Swine" is that Steve Pastis isn't confined to the four walls of his panels. His characters know that they're comic strip drawings, and often interact with a cartoon version of Pastis.
The strip has riffed on some legacy strips, such as "Family Circus." Now most of the current generation of cartoonists treat legacy strips with contempt. "Blondie," "Beetle Bailey" and the like (according to them) have out-lasted their welcome and their tired humor and outdated art should be replaced by something more relevant.
Although Pastis pokes fun at these strips, it's clear that he does so with some affection and respect. In one case, he collaborated with Bill and Jeff Keane of the "Family Circus" to create a gag that spanned both comics.
And he's done it again with another legacy strip, "Dennis the Menace." A recent storyline had Dennis visiting "Pearls" to make it more wholesome (with not the intended results). The same day, and in many of the same papers, that this sequence appeared, so did this "Dennis the Menace" panel by Marcus Hamilton and Ron Ferdinand. Note that the cartoonist is clearly Pettis (or at least his likeness as he portrays it in his strip). ( click on images to enlarge)
Either cartoon is amusing, but put them together and you have a third gag that only those really into the comic world could appreciate.
It's for treats like this that I keep reading!