A play on cork stopper. A type of poop that feels hard but is followed by a fast stream of diarrhea that was previously held in place.
"Dude I thought I had a no wiper on my hands, but it was a cork plopper and I ended up using half a roll."
"I could never squeeze out a Cleveland Steamer, I'm too scared it'll be a cork plopper and I'd drown someone."