Skinning is a very important step in the setup of a character for animation that will allow us to deform a mesh parented to a rig. It should be noted that the term skinning is not directly used in Blender. In Blender, you will generally find the term "Weight" designating the influence that a bone has on the geometry. It is often a long and delicate step, but fortunately, Blender allows us to perform an automatic skinning that is already very clean and quick. This is one of the most efficient skinning algorithms.
Before skinning our character, just as a reminder, we must determine which bones will deform the mesh and which not. This will be done as follows:
We will verify whether the Deform option is unchecked for all deforming bones (Properties | Bone | Deform).
In the Object Mode, we will select the mesh of the Rat Cowboy, then the Armature, and we will make them child and parent (press Ctrl + P and select With Automatic Weight).