Though its one of the most perfectly named living things on this planet, the sea cucumber, on first glance, isn't among the most exciting aquatic species. Distantly related to starfish and sea urchins, the sea cucumber in appearance lacks the brio and allure of its cousins, and except for a few variations among subspecies, the general body plan of the cucumber basically resembles a large, leathery sausage crawling along the ocean floor. Yum.