Crests

From WoWWiki

An heraldic representation with a symbol (device) placed above a shield on a coat of arms.

Sometimes displayed on a small possession (often a 'dogtag' type item) showing honor and pride for your race.

Alliance	Human	Night Elf	Dwarf	Gnome	Draenei
Crest of the Alliance	Icon of Courage	Icon of Wisdom	Icon of the Forge	Icon of Technology	Icon of Argus
Horde	Orc	Tauren	Forsaken	Troll	Blood Elf
Banner of the Horde	Icon of Battle	Icon of the Earth Mother	Icon of Torment	Icon of Shadows	Icon of Blood