This is a Bronze Gorgon head that has been broken off the rest of the piece. Gorgons are a female creature. The name comes from the ancient Greek word gorgós, which means dreadful. Apparently Medusa is the sister of the Gorgons. The Gorgons refer to any of the 3 sisters who had hair of snakes and could turn anyone who looked at her to stone. Images and carvings of the Gorgons were put on objects and buildings for protection, or worn as amulets.
Image Credit: http://www.flickriver.com/photos/dandiffendale/sets/72157613706992749/