The term "ferrous dragon" is quite specific in its meaning. It refers to a dragon made of iron or other metallic substances. However, there are several synonyms that can be used to describe this magical creature. One alternative term is metal dragon, which encompasses dragons made of any type of metal, not just iron. Another option is mechanical dragon, which emphasizes the machine-like qualities of a metal dragon. A third term could be alloy dragon, as it describes a dragon made of a blend of metals. Finally, a fourth synonym could be metallic dragon, which encompasses any dragon made of a metallic substance, regardless of its composition.