This animation is a day in the life of a piece of mail. An envelope has been mistakenly delivered to a place where it doesn't belong. It is forced to tough up and journey home on its own.
I created this using a very simple rig to a very simple model. As a stuffed envelope, it really didn't need much flexibility. There was quite a bit of modeling and texturing to do to create the environment.
This is one of my earliest 3D projects, but still a favorite.