What are your favorite racial physical features or evolutions?

Hi everyone. A while ago on TIL, someone posted that dolphins didn't evolve from land mammals, but instead they evolved from land mammals, and then went back into the sea. That post was so interesting to read and made me think of evolutions in the world of my own fantasy story. <br><br>So I would love to know, what are your favorite racial physical features or evolutions, or simply ideas you've found interesting? It could be from the real world or from other works of fantasy.<br><br>I'll go first. Dolphins are humans who reached a critical mass of good karma.