It is the largest surviving toothed whale, known for its huge head and unique teeth. There are significant differences in the number and size of teeth between genders and individuals, with males typically having more teeth than females. Having larger teeth that can grow up to 20 centimeters long, conical in shape, mainly located in the lower jaw. Teeth may serve a display function during mating and competition for mates, but are not used for predation. The teeth of female sperm whales are usually smaller and sometimes even underdeveloped, with almost no gum exposed. Sperm whale teeth are composed of dentin, a hard tissue that can resist the immense pressure of deep-sea predation.

It is the largest surviving toothed whale, known for its massive head and complex sonar system. The head accounts for one-third of its body length and contains special ear structures that are crucial for their navigation and communication in deep-sea environments. The ears of sperm whales do not have obvious external ear structures like terrestrial mammals, but are hidden in complex structures on the head. Characterized by high adaptability to deep-sea environments, including an inner ear structure capable of withstanding extreme water pressure. The hearing is very sensitive and can detect very low frequency sounds that travel far underwater, helping to locate prey, navigate, and communicate with companions.

Also known as the Ghost Octopus or Vampire Octopus, it is a mysterious mollusk that lives in the deep sea and belongs to the Ghost Octopus family of the Octopus order. Known for its ghostly appearance and unique bioluminescence ability, it typically measures around 20 centimeters in size. The body is gel shaped, very soft, and the skin is almost transparent. It has good concealment in the dark environment of the deep sea. There are wide membrane wings on both sides of the body, which help them swim quickly and elegantly in water. The tentacles are covered with small suction cups and glowing organs that can emit bioluminescence to attract prey or communicate. They feed on plankton, small fish, and other mollusks.

It is a mysterious and enormous marine creature living in the deep sea, typically between 10 and 13 meters in length, but some individuals can even exceed this length. Having huge eyes allows them to capture faint light in the dim environment of the deep sea. The tentacles are very long, two of which are particularly long and are called predatory tentacles, used to capture prey. Muscle tissue is highly developed and capable of producing tremendous strength. Mainly living in the deep sea, food includes fish and other marine organisms such as small squid and fish. Due to living in the deep sea, giant squid are rarely directly observed by humans. In many cultures, it is a symbol of mystery and terror

It is the largest toothed whale in the world and one of the largest surviving predatory mammals. Known for its huge head and unique water spray holes, the head can account for one-third of the body length. Mainly living in the deep sea, feeding on squid and fish, especially giant squid. Distributed in tropical and temperate waters worldwide, typically active in waters deeper than 1000 meters. Large in size, adult individuals can grow up to 18 meters in length and weigh up to 50 tons. The social structure is complex, with intricate communication methods including various sounds and body language. Extremely strong diving ability, able to dive to depths below 2000 meters and search for food.