Let's start with the abbreviated warning "WEWEWEDENME" featured on the fish skin. In German this stands for "Wehe, Wehe, Wehe den Menschen".
This warning fish was part of a hand-colored broadside published in 1616 #Augsburg. If you fancy a detailed look at the single sheet print yourself, zoom in here: http://diglib.hab.de/drucke/38-25-aug-2f-801r/start.htm
But what was the print all about? And why is god delivering a warning message on fish skin you may ask? Well, let's follow this thread.