muggins
noun
°A fool or idiot (especially as an ironic way of referring to oneself) .
"I suppose muggins here will have to do all the work, as usual."
°The act of stealing another player's points because they either mis-pegged or counted up incorrectly. House rules specify whether the mugginser gets the mugginsee's points or whether those points are simply lost.
synonyms: cutthroat, cutthroat cribbage