Found this neat little site a while back, but I forgot all about. It lists the equivalent of "John Doe" for tons of other countries. For example, in Mexico it's Juan Pérez, in Italy it's Mario Rossi...and in Croatia, of course it's Ivan Horvat.
Anyway, check it if you want. Or don't. I just thought it was kind of cool because I never even really considered what other countries would call an unknown person. How could CSI: Croatia exist without being able to say "Our perp is an Ivan Horvat."?? Ya, I just blew your mind!