Matthew - for a free alternative right now. I believe that the old Creature House Expression 3.3 had excellent ai import for old and new ai versions. Microsoft bought the company and discontinued the software, but they did offer the program for free. I think I still have the link if you're interested. Also mayura draw had an old freeware version 2.04 that should still be available somewhere on the net though I don't know where. I can go over my notes and find some other freeware alternatives if anyone is interested? Expression 3.3 is something like 60 mb or so, I don't remember the exact size of it, but it's large ... but awe inspiring and well worth the download.

P.S. I found the link that doesn't go through Windows Live registration
http://download.microsoft.com/download/a/5/d/a5d625a5-2e3d-4e9c-8608-6de48d7b569f/CreatureHouseExpression3_3.exe