I've done this in the past without any trouble, but now I can't seem to get it right. It just imports the skeleton and not the mesh.
What buttons do I need pressed in the import menu? I currently tried it with "apply skin deformation" and "import animation" and then also without having anything selected. Plus a few OTHER alternative combinations.
You should be able to import any creature just with the "default settings". In case you have messed up the settings, just restore default settings and if skinning isn't imported correctly then "use the force Melchior"!!!
Also check nif in nifskope, if it looks as it is supposed to.