I enjoy building specific characters for my classes to help them practice visualizing animations for a variety of characters.
This includes different types of ball rigs, a squirrel rig (basically a ball rig with a tail), a flat pencil-like character and this one-eyed biped named Bob.
Bob is a favorite in my grad animation class and is invariably used in our biped walk cycle exercises.
This is a clip of a walk cycle I animated in our labs this year as I led my students through the process of blocking, splining and clean up. The only thing missing is facial animation (blinks etc.).