He's called the deutsche Michel or 08/15 or Otto Normalverbraucher (and is of course male). I guess they're actually different versions of the typical German. You don't hear his name used much these days though...

The deutsche Michel comes from Prussian Empire times it seems
http://farm2.static.flickr.com/1341/1483110488_ee95e7368b.jpg
he's the guy who has to carry the load for everyone else.

Otto Normalverbraucher comes from the Film Berliner Ballade where a former German World War II soldier returns after being a prisoner of war of the Russians and has to face the fact that the war has been over for four years and he has to adapt to the new Germany
http://www.wdr.de/themen/politik/deutschland/wiederaufbau/kino/_img/berliner_ballade_400h.jpg
These days that's also a placeholder name, much like Max Mustermann.

08/15 can be used to say that something is average, but it's also a film trilogy based on young recruits' experiences before, during and after World War 2. The number comes from a German machine gun that was standard for a long time and then became old-fashioned.
http://german.imdb.com/title/tt0046671/
So if you say that a person is 08/15 it means you find them uninteresting or average.