Northern Germans are called "Fischköppe" (fish heads) by the rest of us, and how fitting is it that I got this picture via fiver2 (thanks!) from Hamburg:

drei köppe zwei fische

It's not just a can of fish, there are also two can openers shaped like fish heads in it, and they are themselves stuck in a head, making that a fish head as well. It's a bit confusing. Trust me on the details.