If you the owner of several green legendary dragons (which you should be by now), Ferrox will hold little value to you. His maximum stats are less than a level 16 Danzig or Hugin, who will rip bases apart much easier than this guy.
No, this guy is a breeder, nothing more.
Breeding Ferrox (link to Amoeba website)
Panda and Naga will breed Ferrox quite comfortably, though you can also look at Nix and Danzig as an alternate route.
Maximum Attack: 48,100
Maximum Health: 451,363