The Dunner gene is a dominant trait so if the dragon is carrying the gene they will display the dunner traits (pattern on the tail, larger forearms, conical scales, etc). Also since the dunner trait is a dominant gene, then there is no such thing as a "het" dunner. If they carry the gene they will show the traits, if they are not showing the traits then they are not carrying the genes. For more info please look at our dunner info sheet.