I tried to create an human in Blender, but it's really hard work.
Therefore I downloaded the "MakeHuman" Tool, it's freeware.
After some modification on its bodyweight (making him fat), I exported it as a "Wavefront" Object.
In Blender you can import Wavefront Objects.
Rendered in Blender:
The cool think is, its possible to modify some "alien" - Settings, deformations ...