Whales are widely distributed and various marine mammals with complete aquatic placenta. They are an informal group of land whales, usually excluding dolphins and dolphins. Whales, dolphins and dolphins belong to Cetartiodactyla, the ungulates with toes, and their close relatives are hippos, which separated about 40 million years ago. The two companions of whales are Mysticeti and odontoceti, about 34 million years ago. Whales include eight extant families: BAL family (family), BAL family (right whale), et family (right pygmy whale), sch family (gray whale), mono family (white UGA and narwhal), phys family (KO family) pygmy and pygmy sperm whale and Zi family (beaked whale).

Whales are creatures of the high seas. They forage, mate, bear, nurse and raise their young at sea. Their adaptation to underwater life is so extreme that they cannot survive on land. Whales range in size from 2.6 meters (8.5 feet) and 135 kilograms (298 pounds) of sperm whales to 29.9 meters (98 feet) and 190 metric tons (210 short tons) of blue whales, the largest creatures ever. The sperm whale is the largest predator on earth. Several species show sexual dimorphism, in which females are larger than males. Whales have no teeth; instead they have a baleen plate, a striped structure that drains water while retaining krill and plankton that feed on them. They opened their mouths with the folds of their throats and drank a lot of water. Balaenids' head can make up 40% of its body weight and can drink water. On the other hand, the conodonts of toothed whales are designed to catch fish or squid. Baleen whales have a very developed sense of smell, while toothed whales have a developed hearing. Their hearing is suitable for air and water. It's very developed. Even blind people can survive. Some species, such as sperm whales, are well suited for diving deeper to catch squid and other popular prey.