Procedural generation of biological models
I am playing with L-Systems and with some thorough understanding of how they work I think you could manage to get something useful out of them. You can see Paul Bourke's site for a sneak peek of what they do and you can read the  book The Algorithmic Beauty of Plants by Przemyslaw Prusinkiewicz and Aristid Lindenmayer. I am going to try and explain what L-Systems do in case the links die, L-Systems are a way of creating simple rules that define the topology of plants/organisms/fractals by simple axioms, this axioms can be rewritten in terms of other rules that can create incredibly organic behaviours, originally this systems were abstract in the sense that they lacked geometric meaning, but over the years people have figured out how to transform this topologies into geometry through interpreting the rules as &quot;directions&quot; much like turtle graphics. I have seen this systems replace basic geometric rules such as &quot;draw a line between two points&quot; into create a complex building with &quot;A or C characteristics&quot; so I think you could define your interpreter in terms of biologically accurate creatures.