I have always been fascinated with this creature. It looks like a robot, it's actually a virus, but certain species kill bacteria that would harm us, so they are good.

Here is a link to the WikiPedia site. Their object looks a little different than mine, but there are many different kinds.

http://en.wikipedia.org/wiki/Bacteriophage

If you like this model you can see more at my blog:
http://thekoalafarm.blogspot.com/

This model was made with Cubify Invent. I added the struts at the bottom to make printing easier, just cut them off to turn your bacteriophage free!