I have seen Eunice aphroditius worms that werent out of the hole all the way and were over 5 feet long in the Keys. As big around as a ping pong ball. They look like that,and they have 4 fangs that are at 4 sides. They can see too, as I pull some algae away from it, and it would grab it with its fangs, and pull it back. It was kind of spooky, because it going out 5 feet, and I was in 4 feet of water, and fairly close to it. They are found around the world.