n. (context informal English) A game in which the first player to call "Punch buggy!" on sighting a Volkswagen Beetle gets to punch the other.
Punch buggy (also called punch bug, punch car, punch dub, piggy punch, slug bug, or beetle bug) is a car game generally played by children in which participants punch each other on the arm upon first sight of a Volkswagen Beetle while calling out "Punch buggy!" or "Slug bug!" in reference to the Beetle's nickname, the Bug. The color of the Beetle is also stated.