It is likeliest that Ferrovax is the dragon that Odin has contended against in many of his identities as Odin the Midgard Serpent, Beowulf’s Dragon etc. Currently Vadderung/Mr Ferro are probably business competitors.
There is even a story involving Saint Nicholas (Kringle) charming a Dragon, according to the St Nicolas Centre website, as one of his miracles. Vadderung has probably popped up as numerous Dragonslayers in mythology, and the Dragons were probably all Ferrovax. Perhaps they have been running a con for many, many years, Ferro turns up and terrorises an area, only for a dragonslayer (Odin) to step forward and ‘slay’ the dragon. A grateful populace showers wealth on Odin which he splits with Ferro who is very much alive.