How to open a custom creature from NifSkope into the Creation Kit

[DoctorDinosaur]

So I replaced the Mesh for a Dragon with another creature (obviously the bones won't work),

but besides that fact how do I get this custom creature to show up on the Creation Kit.

 

The file extension is Gamebryo.

 

I have tried clicking and dragging, I Google'd before hand but no one told of how to add this creature specifically.

 

What do I do?