Commander's Badge shows off your ranking among the Dragonmaw orcs.
This trinket is a quest reward from the Netherwing quest  . The quest starts with Taskmaster Varkule Dragonbreath when you become revered with Netherwing. Simply speak with Overlord Mor'ghor to complete the quest.
The whelp summoned by this item scales with the players level, making it still slightly useful in early Northrend zones for solo players as well as for just aesthetic use.