Blender is GREAT software, the function is more than enough for 3D animation. The community was GREAT too like the software, you can download many thing source file! For what? You can use it for education, commercial and other, you FREE to use the source! Sometime, when i've download source file i don't understand what the creator use for it, so i must surf in blog to understand. There is, i want share, how to create custom shape rig.
When you download the source file, sometimes you can't find the bone / armature, but you just need to move in pose mode variety of shape. You can call it custom shape. Because the function is same like bone, the custom shape rig just change the rig shape into what we like. There is the example of shape rig.
|custom shape example|