Def. 1: A device made solely from rolled up toilet paper, resembling a make-shift tampon, which is inserted between the ass cheeks -- however not necessarily plunged into the anus -- to alleviate the feeling of "wet-ass" a person (usually a male) experiences when the feeling of wetness is felt post wiping after a person takes a shit.
Def 2: Butpon refers to the user of an anal-region tampon to alleviate the uncomfortable feeling of "wet-ass" experienced after taking a shit.
Example 1: My little brother came hauling ass outta the bathroom, and a rolled up piece of asswipe fell outta his pant leg, which was of course the aformentioned almighty "buttpon." I was like "what the fuck is that!?" and he then explained his feeling of "wet-ass", therefore the "buttpon" was invented.....
Example 2: "You are such a buttpon!"