Ferrovax

Ferrovax is a Dragon. He is also known as Mr. Ferro. He first appears at Bianca's Ball in Grave Peril.

Description
Ferrovax was present at Bianca St. Claire's masquerade party; he was wearing the authentic armor of a Roman centurion and had smoke coming from his mouth while holding an unlit cigarette.

Ferrovax is the eldest of his kind, and the strongest of the Dragons. He displays immense magical power with only a wave of his hand, and claims there's power with the use of someone's name. There also seems to be something in the Lore that says not to use a name other than his full name.

Grave Peril
In Grave Peril, Harry Dresden met Mr. Ferro at Bianca's Ball for the first time. Michael pointed out to Harry that he was a dragon. When Ferrovax told Michael and Harry to call him Mr. Ferro, Michael refused. Ferro said that Michael knew something of the Lore, at least for a mortal. When Harry stood up to his bully-ish display of ego, he crumbled Harry to the floor with a simple wave of his hand. Michael told Ferro that he slew the Dragon Siriothrax and he said: "So you are the one."

Later at the Ball, on behalf of Bianca St. Claire, he was handed a gift by a hooded figure—identified as Cowl later in the series —that he considered impressive.

Speculation
It is possible that Ferrovax is also infected by the Outsider, Nemesis, with the gift presented to him at Bianca's Ball, as Lea was affected by The Athame she was given at the party.

Word of Butcher
According to Jim Butcher, Ferrovax will appear again in the final books of the series.

Quote

 * "Don't tempt me to show you what I can do by speaking your name and making an effort, mortal. suffice to say that you could not comprehend the kind of power I have at my command. that my true form here would shatter this pathetic gathering of monkey houses and crack the earth upon which I stand. If you gazed upon me with your wizard's sight, you would see something that would awe you, humble you, and quite probably destroy your reason. I am the eldest of my kind, and the strongest. your life is a flickering candle to me, and your civilizations rise and fall like grass in the summer."