I love this bat. The model is by Anna Kastlunger, and the diagram can be downloaded.
I love that it is simple-looking, yet very recognizable.
I was at a science-fiction convention last week-end, and distributed a huge bag of origami – people called me the origami faerie, it made me very happy to see the paper joy spead! The person who took this one seemed to have fallen in love with the model :)