Created in the Year of the Black Water Rabbit. So how could I resist creating a California black sea hare? Aplysia vaccaria is the largest member of the group of seaslugs known as sea hares, the biggest individuals coming in at over 3 feet and a massive 30 pounds. The gentle giants are vegetarians, and they eat brown algae, which gives them their dark coloration. Despite being large and squishy, and the only sea hare without defensive ink, the black sea hare has no known predators. It's thought to derive toxins from its diet.