An insult that is given when one is of a disgusting nature. 'Pigger' is derived from pig and snonk is the noise emitted while expelling mucus from one's nose. Typically, this insult is given in the lower age group of 6 - 12 years old.
Ewww gross! You Piggersnonk!
You friggin piggersnonk did you just eat that mucus you expelled on to the floor?