My guess would be Prester John, but it’s just a guess.
Nah...I googled it...
“In the dexter corner (to the left of the person looking at it) is a Moor’s head in natural colour [caput Aethiopum] (brown) with red lips, crown and collar. This is the ancient emblem of the Diocese of Freising, founded in the eighth century, which became a Metropolitan Archdiocese with the name of München und Freising in 1818, subsequent to the Concordat between Pius VII and King Maximilian Joseph of Bavaria (5 June 1817).
The Moor’s head is not rare in European heraldry. It still appears today in the arms of Sardinia and Corsica, as well as in the blazons of various noble families. Italian heraldry, however, usually depicts the Moor wearing a white band around his head instead of a crown, indicating a slave who has been freed; whereas in German heraldry the Moor is shown wearing a crown. The Moor’s head is common in the Bavarian tradition and is known as the caput Ethiopicum or the Moor of Freising.”
http://www.vatican.va/holy_father/benedict_xvi/elezione/stemma-benedict-xvi_en.html
See post #10.