This was a really fun project! I went through the Wikimedia Commons page to find some good candidates for the transformation. I was mainly focusing on interesting animals and textures. A few of the options I pulled are below.

In the end, I decided to use the barnacle picture in the lower left. I isolated the actual animal, and duplicated/mirrored it over the four quadrants. I then used the different layering multiplication styles to create several variations of the design.