3D model of the water bear or tardigrade (Echiniscus species) - possibly the most widely spread and amazingly adaptive multicellular animal on Earth. They are cryptobiotic and have been demonstrated to be able to survive exposure to outer space for extended periods. The animals are about 0.5 to 1.0 mm long, so this is a 60X blow-up.
The original model was passed on to me by a colleague some time ago so I can't give a provenance link. I made very minor mesh cleanups with Rhino3D and printed it on a Replicator with 1 shell at 10% infill. Details such as the claws on the end of the "feet" come through nicely although the extended feelers on the model get truncated in the print.