Once at a social gathering, a friend of mine was telling a joke, and laughed so hard at his own joke that he snorted. A nearby girl asked him, "Did you just snort?" My friend, ever quick-witted, came back with this clever but confusing reply: "No, that's just the pig I'm sitting on.".
Of course, he wasn't sitting on a pig at the time; he just said that because it was a clever way out of an awkward situation. I so admired his wit that I drew this cartoon so that it could be memorialized. In the cartoon version, I decided to draw an actual pig underneath his seat -- I'm not sure whether that adds or detracts from the punchline.