Metal Horn Unicorn Tribe Heraldic Symbol Trading Cards. In the tribe of metal horned unicorns, each herd is represented by a Herd Crest.  The Water Purification Herd Crest shows a copper cup with the alchemy symbol for water emblazoned on it.  The Medical Herd is represented by a stethoscope with a unicorn shape in the tube.  The Empath Herd Crest has an open heart surrounding the Celtic symbol for love.  Read about the different Metal Horn Unicorn herds in the Blue Unicorn’s Journey To Osm books and start collecting the Tribe of Metal Horned Unicorn Trading Cards, too.