I'm not sure about your question
Yes, I think, it's easier to make all 50 Monsters in Photoshop (or wherever) then position and stack different bodys/heads/eyes inside C2.
If your question is about the details/stats of each monster - I would look into XML. Not the easiest to understand, but very flexible.
Here you can write down every single property of your monster and fetch whatever you need out of the XML
way more detailed