With the upcoming addition of a more friendly weaponsmithing system, I think it would be fun to have creatures that are more susceptable to non-standard metals.
There's the classic warebeast and silver, but it might be fun to have something suscepable to lead or copper.
Hunta Talna Kortok, built by Gor'Togs, for Gor'Togs
http://www.angelfire.com/rpg2/caraamon/home.html
Blunts for Sale:
http://www.elanthipedia.com/wiki/User:Caraamon#Wares
Combat Balance Sheet:
http://www.angelfire.com/rpg2/caraamon/balance2.xls