I really like your sheep.
Re "I also agree that the head could look both ways, but I'm not sure how to get that nifty 3D-effect rig to work so that it can achieve that effect"
The slot that holds the head could have some extra attachments in it for frames of the head switching to the other view. Unlike your other assets that tween with meshes to produce a great 3D look, those head turn frames would probably have to be hand-drawn. To cut your work down, you could make the head switch really fast and use a blur effect.
The head-turning might not be valuable for your project. I just think it would look cool.