You might be tempted to describe your greedy lunch companions as porcine, but you should try to resist the urge. Porcine means "like a pig."
The adjective porcine is a scientific term for talking about pigs, but it's also useful for describing anything — or anyone — resembling a pig. A large, shiny-faced man might appear porcine to you, and so might a group of hungry kids who shove and jostle each other to get their hands on a plate of brownies. The Latin root is porcus, or "pig."