In my case however, the sand dollar was alive. I had never seen a sand dollar with it's whole body before and it took me a little while to figure out what it was. I put it on my hand and its thousand little "tentacles" wiggled and twisted. It was one of the weirdest feelings I've ever experienced. I ended up taking it home and setting it down. One really strange thing it did was when any fresh water substance touched it, it would ink this yellow substance out, which would then permeate and dye your skin. I put it on some rocks and took a picture of it and this is what I got.