A man who chomps on the mop. Or in simple terms, eats vagina. A more colloquial version would be, rug muncher. Both mop chomping and rug munching are the act of eating out the vagina.
"I walked in on eric eating out liza, what a mop chomper."
"Eric's breath smells like fish, he must have been mop chomping all of last night." (mop chomper)
"That's not what your mom said when i was mop chomping her last night" (mop chomper)