Ferrovax

Ferrovax is a Dragon that was seen in Grave Peril masquerading as a Roman Legionary.

Biography
When Harry Dresden met him at Bianca's masquerade party, he was wearing the authentic armor of a Roman Legionary and had smoke coming from his mouth while holding an unlit cigarette.

He displayed immence magical power by staggering Harry while only using part of his name with minor effort.

He was handed a gift at Bianca's party by Cowl that he considered impressive.

According to Jim Butcher he will appear again in the big apocalyptic trilogy