There's a program called sPatch that can create *.mdl files with organic-type shapes.  I haven't really worked with it much, but the interface seems simple enough.  Should be easier than making tons of unions/merges/differences/whatever else moray does  
You used to be able to get it on the moray site, but I think you can only get the patch to make it work with moray now (you'll need that too).  A search on google should bring it up though.