Currently in vanilla there are 'iron men' but no animate peoples for the other metals. Rather than modding in a whole creature, i put them all together in one creature as separate castes. These come with a population ratio very loosely based on the rarity of the metal. No alloy or adamantine are included as castes.

Currently each has the same syndrome caused by their internal gas with a different name. This may or may not change in the future.

-Tweaked population ratio numbers
-Fixed a couple bugs. Each caste should now be the right color and drop the right kind of statue on death.

*EDIT* Updated for DF 2014