Sperm whales belong to physeteridae, the largest species of Toothed Whales. The maximum length of male is 23m, and female17m. Their bodies are conical, and their maxilla is blunt, far exceeding their mandibles. Because of its huge head, it is also known as the "giant whale". The top-heavy body of sperm whale is very suitable for diving. In addition, they like to eat huge cephalopods, most of which live in the deep sea. Sperm whales often "hold their breath" 1.5 hours because of chasing giant squid, and can dive to the deep sea of 2200 meters, so they are the champions of mammalian diving.

The biggest squid in the world is the king squid. They generally live in the depths of the ocean, rest in the deep sea during the day and swim to the shallow sea for food at night. Generally, the juvenile king squid is 3-5 meters long, and the adult king squid can be as long as 17- 18 meters. The king squid lives in the deep waters of the Pacific Ocean and the Atlantic Ocean. It is about 20 meters long and weighs about 2-3 tons. It is the largest retarded vertebrate in the world. Its temperament is extremely fierce, it feeds on fish and invertebrates, and it can fight with giant whales. It is often reported abroad that the king squid fights with the sperm whale. According to records, once a king squid was witnessed holding a sperm whale tightly with its thick horn hand and sucker, and the sperm whale tried its best to bite the tail of the king squid. Two behemoths in the sea rolled violently, stirring up turbid waves, and then both sank to the bottom of the water, not knowing where to go. Most of this kind of struggle is that sperm whales win, but there have also been cases where the king squid strangles whales by holding their nostrils with their hands.