I thought you all might find this interesting:
Making a mob variant is as easy as copying the .an8 file and making your changes. Unfortunately Anim8or isn't very good for UV mapping, so I use Ultimate Umwrap 3D for that, and I import the object back into Anim8or when I'm done (with the extra step that UU3D reverses the polygon normals for some reason so I have to flip them when I re-import back into Anim8or).
One major driver for making a gnoll is that my test database that I plan on releasing with SimpleClient has gnolls infesting the Canyons of Gur, and for the moment I have the hook horror models taking their place. When I have proper gnolls the hook horrors will take their rightful place somewhere underground...