Ever Drifting, Drifting, Drifting

Pure loveliness, found at a train station in Duesseldorf. You can almost hear the waves caressing the tendrils of seaweed this way and that:

Seaweed-Shaped Graffito

Note the balding egghead to the right of the graffito with the question mark over his head. You see him everywhere -- does anyone know his story? 

There seems to be a lot of outstanding graffiti street art in Germany. Has anyone written a book about it that one of my good-looking, cultivated readers can recommend?