bumcoppers 

small, pebbly, rusty-looking plops that havent been flushed and which resemble mucky old coins in a fountain.

look at how these bumcoppers have tarnished the surrounding toilet water and made it all rusty

bumcoppers by johngo August 6, 2011

Bumpopper 

Your butthole

Ow I have a dingleberry stuck to my bumpopper

Bumpopper by Monster poop June 5, 2017