Hammerhead Shark: Official Sea World Marine Mates Talking Plush Stuffed Animal Hammerhead Shark: Approximately 15 inches long. Says: I'm a Hammerhead Shark. I make no sound; Also says: I have no bones. My skeleton is made of cartilage. Also says: My wide head helps me swim, see, and hear really well. Sample fact from tag (1 of 5): They swim in schools, which can consist of hundreds of Hammerheads. More details below.