Another moniker for the Jesus Fish.
A play on Gefilte Fish, the stinky fish snack; Gefahr in German means DANGER. In other words when in the company of a person of the Gefahrte Fish, be prepared for hypocracy, back-stabbing and gossip of the highest order. Virtually nobody is free from the wrath of the Gefahrte Fish, meaning the only ones not being damned are the ones who happen to be present at the moment.
The Gefahrte Fish is typically seen on the back of cars and harleys driven by middle aged women who frequent crowds of similar age - usually letting everyone in the place know how righteous said woman is. Usually the same car or harley can later be seen parked at bars frequented by 20-something males.