With the Animation... why don't create the new animations for the critter with the original critters "in background"? Don't know, how to describe it... a kind like.. you make a screen from the animation position 01 from the critter xyz. You set your view in the animation programm (3ds max or something like this) like the iso-view in fallout, that you see the figure like you would see it in the game.. then you create the first animation move with the pic 01 from the critter animation...
Aehm... I try to explain it on an other way...
- make a screen of critter xyz in animation pose 1
- put this screen in the background of your animation programm
- load the new 3d model
- adapt your viewpoint -> new 3d model position must be like the model on the screen in the background
- then you create the first step of the animation
after this:
- load a screenshot from critter xyz with the animation pose 2 in the background
- possibly adapt your viewpoint again
- create the next step of the animation
and so on.. so long till you have all animation steps created. Then save or watch, how it looks like.. if the animation is done, you can make screens from the new animated critter - rotate the viewpoint, so you don't need to create the same animation for six player directions.
Once an animation is done, you can use it for other new 3d models too.
Know what I mean?