Umbrog is one of the two current Lieutenatrons. He is known to be the only dwarvish officer of the Guard ever. The part what makes Umbrog's uniform so unique, is his Mining Hat.
He is also known to have a secret cruss on a seven feet tall pink bunny a.k.a. his shirt.
If one were to search for Umbrog they should search in the inn's or any place that there's recruits to be yelled at.
Umbrog Steelhammer was born in Dun Morogh as many other dwarves and lived a happy life there filled with boozing and mining and brawls. All this changed when a injured gnome called Anterix fled gnomeregan and Umbrog found him. The gnome later convinced Umbrog to follow him to live a life in Ironforge. They did so and there they started a union-like company 'The Workers of Ironforge'.
After some time when the company had failed they moved on to Stormwind in their pursuit of happiness. There they lived doing a little bit of this and a little bit of that until the day they joined the Gigaflux Guard.