Let's do the rig of the Rat Cowboy. We are not going to show the modeling process here as you already know how to model proper characters from the Alien project.
The first thing that we will need to do for our rig is place the bones that will directly deform our mesh. These are the main bones. In Blender, a rig is contained in an Armature object, so let's go!
Let's begin with the process: