An Art Nouveau masterpiece for the granddaddy of all horror movies!

This 1922 poster is glorious!  I particularly like his posture and how the text sweeps across him.  The rats leaping in a wave is another great dynamic element.  So, so cool.  They truly do not make ’em like they used to. I have been trying to find out who the artist of this poster is, without much success. If anyone figures it out, please let me know.  Hint… it might be something having to do with the signature “RAU” in the corner… but that didn’t lead me anywhere.  Where’s Antiques Roadshow when you need them?