English: Hermes Trismegistus.

From English Wikipedia: en:Image:HermesTrismegistusCauc.jpg, stating: "It is obvious that this is one of many, many pictures from the Middle Ages or Renaissance of this subject. It has been scanned and put on the Internet by someone, who is not credited on the site this was received from. This same image appears more than once on the first page in Google's image search under "hermes trismegistus". Seeing as the author, being mortal, certainly died centuries ago, there should be no problem with copyright infringement.

Further research indicates that the image is 'Engraving of Mercurius Trismegistus from Pierre Mussard, Historia Deorum fatidicorum, Venice, 1675.' This information was obtained from Adam McLean's Alchemy website: http://www.levity.com/alchemy/amclglr9.html.