A miniature carving of a Rat Terrier I did for a fundraiser for the rescue I'm a member of. I've done quite a bit of miniature work, in part because the first SHARP tools I got were when my dad gave me a set of Exacto knives/blades for Christmas on year, moving me up from the not so sharp pocket knife I was carving with. Working with SHARP blades, I was amazed at how much more detail I could do and on what a small scale.
The tiniest stuff I've done was a collection of tiny animals that would fit inside a walnut shell which was cleaned out and hinged together with a bit of fabric then lined with fabric. These were sold in the Silver Dollar City woodcarving shop the summer I worked there. At that scale they were not as detailed but you could easily tell what the animal was. If I can still find one, I will post a picture.