Year by year, we see more and more robots that mimic animals, like for example the snake robot. This time, we go underseas. This new evolutionary robot is developed in the Northwestern University. It is called GhostBot, and it copies the propulsion mechanism or the black ghost knifefish. This fish, has only one single horizontal fin (like a knife blade) which uses to propel itself forwards, backwards and straight up. If this bot works 100%, it will probably change many aspects in submarine propulsion mechanisms (and not only).