BAT RAY by Nia
Talking about Nia's Bat Ray tessellation is a good place to mention that some themes are vastly more popular than others, in tessellation art. Birds, fish, rays in particular, and lizards are all very well represented in tessellation art. Take a peek at some from this website: Stingray by Claire P., Stingray by Claire P., Three Fish by Ozplasmic. M. C. Escher himself has donea few ray tessellations (one, two, three).
You'd expect that with such a standard easily recognized shape, there would be some repetition in all that ray tessellation art. But, nooooo. Somehow, each artist finds a way to make the art different yet recognizably a ray.
To read more about popular themes in tessellation art, click on this link. The essay's funny, with lots of illustrations. I guarantee you'll enjoy it.