The dead man's finger is a soft coral, just as hard as cartilage. The branches are totally covered with small polyps. The polyps themselves have eight tentacles, but they are only visible with a very good magnifying glass. The polyps are readily frightened. If you were to brush against a dead man's finger, the polyps retract quickly into the coral skeleton. They only dare to come back out after several hours. If you don't see the polyps, the coral structure looks like a leathery finger.