Referring to an individual defecating and/or on one's self or others. May or may not be sexual. Also can have random occurrences, often fun to do at a water park with butt pirates. It is an insult to be dubbed a mystery nugget to African Americans. To be called a mystery nugget one should respond with a smile.

When some little bitchboy is acting like a little tiny pee pee poo poo baby and messing up the group plans.