Walrus is a carnivorous mammal in the family Walrus, which has only one species and no subspecies. Walrus has a cylindrical body, thick and obese. Flat head, blunt snout. The forelimbs are relatively long, and the fingers are spread apart; The hind limbs can bend forward, allowing for crawling on land and swinging left and right while swimming. The tail is very short, hidden in the skin behind the buttocks. Male white upper canine teeth grow continuously throughout their lives, with their roots attached to the upper jaw and a very strong connection to the skull. The tips extend out of the mouth to form elephant like fangs, hence the name.

Pig is a vertebrate, mammal, domestic animal, and also an ancient omnivorous mammal, mainly divided into domestic pigs and wild boars. Currently, people believe that pigs are the abbreviation for animals in the pig family, and pigs have different physical characteristics depending on their breed; Usually characterized by large ears, long head, short limbs, straight nose, fat body, and narrow waist and back. The hair is coarse and hard, and the fur colors are usually white, pink, black, brown, and floral. Domestic pigs are a subspecies of wild boars that have been domesticated by humans. They have shorter tusks than wild boars and are one of the domesticated livestock. Generally speaking, domestic pigs refer to pig breeds that humans raise for food.

The central organ of vertebrates. The main function of the heart is to provide power for blood flow and to move blood to all parts of the body. The human heart is located in the middle of the chest to the lower left. It is about the size of a fist and weighs about 250 grams. The human heart is shaped like a peach, located above the diaphragm, between the lungs and to the left. In September 2022, Australian researchers found a 0.38 billion-year-old heart in the fossilized jaw fish.