This would involve a re-skinning, which isn't that difficult, but is time-consuming. (Testing, getting the colours right, etc.)
I'd encourage you to fiddle with the tga, however (as soon as you find it - there are a LOT of placeables. :S ) - if nothing else, you can stick your modified .tga in your override folder and have the dragon of your dreams there, at least.
Things you'll need to get started:
And here's a brief
how-to from the BioBoards.
Have fun experimenting!
