This Alien model is textured with high resolution (4096 x 4096) textures for colour, specular colour and normal map. There are lower resolution maps for noise and Vector Displacement. Users of the non native files should be aware that the displacement is a vector displacement.
There is also a folder with bonus textures including an alternative base body texture and a cavity map to facilitate the creation of custom colour maps.
To render correctly, the following Mentalray subdivision levels have been set in the Maya scenes: The Body: Level 2 The Teeth: Level 1 The Eyes: Level 1
The Maya file has a Subdivision proxy driven by a low resolution Alien. I recommend to rig the Low Res Alien and maintain the history of this subdiv proxy for rendering, not just a subdivided lowres version. I have tweaked the corners of the smoothed UVs on the subdiv proxy, and so only the subdiv proxy will render seamlessly in those corners.