In many German areas these carnival customs were lost after the reformation since the Protestant church got rid of the days of lent before Easter. In Catholic areas, however, carnival continued to be celebrated. In the towns the festivities were organized by the guilds, while the nobility held balls and masquerades in their palaces and estates. Carnival masks and costumes became more and more intricate and elaborated and were influenced by the Italian commedia dell' arte. The modern forms of carnival can be traced back to the 19th century during the years of political restoration in Germany. Modern carnival emerged as a middle-class effort with strong elements of parody of politics and the military.
Today you can find two very different forms of carnival in Germany: on the one hand you have the (political) Rhinelandish carnival (Karneval, Fasnacht, Fassenacht) with show events which combine song, dance, and speeches, and carnival parades. The strongholds of the Rhinelandish carnival are Cologne, Düsseldorf and Mainz, where the parades are held on Rose Monday, the Monday before Ash Wednesday. On the other hand, you have the Allemanic Fasnacht in southern Germany, where at the beginning of the 20th century the old forms of carnival with wooden masks were renewed. By now, each village, town and city has its own figures and masks. Here's a pic of the witches of Waldkirch (a small town in the Black Forest, which I used as a model for my fictional town of Kirchwalden in CASTLE OF THE WOLF) during the witches' sabbath on the market square:
In the following you can see some pictures of the Rose Monday parade in Mainz: