Goog oyster
A predecessor to the "mung barnacle", the goog oyster is a relatively large, moist, collection of shmutz found at the corners of the mouth. The "goog oyster" is usually found on ones mouth after excessive narcotic consumption, an extensive conversation with greg, or caused by excessive dairy consumption.
"Oi methbreath, wash off them goog oysters and brush ya fukn teeth, you smell like Shmidt".