Mike Sorrentino was a minor character who appeared briefly in "It's a Jersey Thing". He was seen tied to a chair right before the Jerseyans started advancing upon South Park. Randy Marsh interrogated him. When he replied, "It's a Jersey thing", Randy starts beating him up, asking what he means.
He wears a white shirt, a tan vest emblazoned with a decorative "S" near the right shoulder, a belt with a buckle bearing the letters "TS", and blue jeans.
He seems to be unintelligent, to the point of not being able to explain what "It's a Jersey Thing" means, although, several other Jerseyans were the same way, so it is likely he is of average intelligence among the other Jerseyans.