The Triple Horn of Odin is a stylized emblem of the Norse God Odin. This symbol consists of three interlocked drinking horns, and is commonly worn or displayed as a sign of commitment to the Asatru faith. The horns figure in the mythological stories of Odin and are recalled in traditional Norse toasting rituals.

The symbol above the rider's head is the triple horn:

Related Resources:

• Asatru
  The customs, history, and links on Norse Spirituality on About.com.
• The Havamal (sayings of Odin) 
• Asatru symbols
  Emblems of Norse religion illustrated and explained.