Nine sons of the dragon “Hoai Nam Tu”, a book by Liu An (179 BC - 122 BC) is an early written document introducing many types of dragons: Phi long, Ung long, Giao long and Tien long. These dragon images have many characteristics of real animals such as birds and fish. Later, the dragon image was created with the regulation of “nine similarities”, including: Deer horns, camel head, demon eyes, snake neck, clam/clam belly, carp scales, hawk claws, tiger feet and cow ears. On the dragon’s head there is something like a bump, if the dragon does not have this bump, the dragon cannot fly. To support the ability to fly, wings were added; similarly, the mane and beard. Not only the dragon symbol but also in history, the nine sons of the dragon (long sinh cuu tu) are also favored by Vietnam and Northeast Asian countries, including: China, Japan, Korea and South Korea. The image of this dragon “family” is depicted based on the combination of the legendary creature - dragon and real-world animals.

The legend of the dragon giving birth has existed for a long time, mentioned in literature such as: "Pre-Qin and Two Han Dynasties" or in "Historical Records". But it was not until the Ming Dynasty that there were notable records: "Hoai Loc Duong Tap" by Ly Dong Duong (1447 - 1516), "Thuc Vien Tap Ky" by Luc Dung (1436 - 1494), "Thang Am Ngoai Tap" by Nhu Duong Than (1488 - 1559), "Ngu Tap Tro" by Ta Trieu Chiet (1567 - 1624). The records about the dragon's children are very rich, the content also has some differences, but basically it can be generalized that: The dragon gave birth to nine children, none of which are dragons, they only have a few characteristics of a dragon. There are two main theories about the dragon's children, with different orders. The first theory is that the order of the dragon's nine children is: the eldest son Tu Ngu, Nhai Te, Trao Phong, Bo Lao, Toan Nghe, Ba Ha, Be Ngan, Phu Hi, and the ninth son is Xi Van. Another theory is that the order of the dragon's nine children is: the eldest son Ba Ha, Xi Van, Bo Lao, Be Ngan, Thao Thiet, Cong Phuc, Nhai Te, Toan Nghe, and Tieu Do. In all, there are twelve images that are considered the children of the dragon. Because the dragon is a spiritual animal, its children also carry that spirit, bringing luck and good fortune to the places where they appear. Depending on the personality of each animal, people use their images to decorate different places such as doors, utensils, weapons, and musical instruments: - Tu Ngu has the shape of a small dragon, yellow in color, with horns like a unicorn's horn. This species is very fond of music so it often chooses the head of the instrument to sit on, and because of that, the ancients often used the image of Tu Ngu to decorate instruments. - Nhai Te has a wolf-like appearance, with dragon horns, the horns grow long towards the back. This species has fierce eyes, an aggressive temperament and a thirst for killing. Based on this characteristic, Nhai Te is often chosen to carve on weapons, both for decoration and to increase the intimidation and damage. - Trao Phong is often adventurous, likes to climb and look far away. Therefore, this species is often carved on the top of columns, roof corners of houses or some high points on architectural works with the meaning of fire prevention, chasing away demons. - Bo Lao originally lived near the sea, but was very afraid of whales. Every time it encountered a whale, Bo Lao often cried very loudly. Therefore, Bo Lao was often cast above the bell, implying that the bell's sound would resonate far. - Toan Nghe has a lion's body and a dragon's head. However, unlike its noisy brothers, Toan Nghe lives a rather quiet life. This species only likes silence and often sits still watching the incense smoke rise. Therefore, Toan Nghe is often carved above incense burners. - Ba Ha has the shape of a turtle and a dragon's head. Ba Ha loves to carry heavy objects, so it is often decorated at the foot of columns or stone steles. - Be Ngan has the shape of a tiger, with long and sharp fangs, and has great power to show off. Be Ngan is very assertive, righteous, loves justice and often argues for justice. Therefore, Be Ngan is often decorated at the gates of prisons, government offices... or places related to law and trial. - Phu Hi has the shape of a dragon, but has an elegant appearance, often curled up on rocks. Phu Hi loves to look at the inscriptions on steles, often lying down to look at the inscriptions. Because of this strange hobby, Phu Hi is often carved in pairs, balanced on steles. - Xi Van lives in the sea, has a head like a dragon's head, tail, fins, wide mouth and short body. Every time it hits its tail on the water, water shoots up to the sky and obscures the sky and earth. According to legend, Xi Van likes to watch the scenery and often helps people put out fires, so it is carved as a decoration on the roofs of ancient palaces, pagodas, temples... implying to pray for fire suppression and prevent fires. - Thao Thiet has big eyes, a wide mouth, and a strange appearance. This mascot is extremely greedy. Therefore, it is cast on eating utensils as a reminder for people not to be greedy and become impolite. - Cong Phuc likes water, so it is carved as a decoration on constructions or means of water transport such as: bridges, water canals, dams, wharves, boats... with the wish that Cong Phuc always contacts, manages, and looks after the amount of water serving the people. - Tieu Do likes privacy, often curls up into a snail and does not like others to invade his territory. The map is often carved on doors or decorated on door handles, implying privacy and safety for the homeowner.

Comparing Vietnamese dragons and Northeast Asian countries The image of the dragon in China when spreading to Vietnam, Korea, North Korea and Japan has developed and been used differently according to different discourses to suit the tastes and social elites. The reason for these differences is the different natural and social conditions of the countries. The image of the dragon was originally used to express the aesthetic thinking and ideology of each sculptor or painter, but was later covered with a set of values, expressed in many different roles, shapes and colors. From there, dragon symbols can be different between Vietnam and Northeast Asian countries. Although influenced by Confucianism, in countries outside of China, there still exist unique characteristics in the role and meaning of the dragon symbol. While in China there was a ban by the emperor on the worship of dragons among the people, in Vietnam there is a prevalence of decorative dragon images in many local temples and pagodas. In terms of role, one of the common points in most countries is that dragons play a role in protecting and sheltering people - this is one of its longest and earliest roles. In the chapter Thien van huan of the book "Hoai Nam tu thiet la vu co" (The Universe) is divided into four directions and a central region. Each of these regions represents an element (wood, fire, earth, metal and water) and has a directional deity including the Azure Dragon/Hoang Long, the Vermilion Bird, the Tiger, and the Warrior. These images help protect people from evil and they are often used to decorate palaces and architectural works. Historically, dragons are believed to have connections, being one of the directional deities that govern the East. Like the image of dragons in other countries, Vietnamese dragons are often understood as guardian gods, bringing happiness and peace by controlling rainfall, helping people have a prosperous life. But in some cases, Japanese dragons are also considered a symbol of destruction, bringing many disasters. Besides, dragons in Vietnam, China, North Korea, and South Korea occupy the most important position in life when they are always a symbol of good fortune, but in Japan this is not clear. Japanese dragon motifs are just one of the popular images in Japanese art and culture after the symbols of Kirin, turtles and phoenixes. In terms of shape, there is a big difference in the description of dragons in Vietnamese art and fine arts and those of Northeast Asian countries. If during the Ly - Tran dynasties in Vietnam, dragons decorated the palace or the king's belongings, their feet often had three, four or five claws depending on the form of decoration, whether it was a round statue or a relief. But in the Le Dynasty, it was completely different, the dragon image always had five sharp claws on its feet. In the Nguyen Dynasty's regulations, the five-clawed dragon was reserved for the king, the crown prince used the four-clawed dragon image, the three-clawed dragon was for the common people. In China, the five-clawed dragon symbolized power and royalty, the four-clawed dragon symbolized supernatural powers (gods, Buddhas) and the mandarin class, the three-clawed dragon was for the common people. However, in Japan, most dragon images only had three claws. This is the difference in each country's concept of the number of claws of dragons in Vietnam, China, Japan, Korea and South Korea.

In terms of color, unlike the dragons of Vietnam, China, North Korea and Korea which are painted in many different colors, the Japanese dragon has two main colors: blue and black. The blue dragon symbolizes beauty and nobility; while the black dragon symbolizes luck because people believe that the black dragon can help create rain and bring prosperity. In Vietnam, China, North Korea and Korea, dragons may vary in feudal dynasties, however, the image of the Japanese dragon shows uniformity in shape (three claws, blue and black) and meaning (symbol of goodness and symbol of destruction). Because Japan has a special environment of islands, harsh climate conditions but has almost absolute unity between people and culture. Therefore, the Japanese dragon also shows consistency in shape and meaning. Unique features of the Vietnamese dragon symbol The Vietnamese dragon has shown the characteristics of geographical diversity by region. To a certain extent, the dragon in Northeast Asian countries is a symbol of power; while the Vietnamese dragon is also a representative of a supernatural being that helps the poor. The dragon in Vietnam is also more widely popular and closely associated with the daily life and folk beliefs of the Vietnamese people through the images carved in village temples. The Vietnamese seem to submit to the dragon and its power. The role and meaning of the Vietnamese dragon are clearly shown in Vietnamese idioms and proverbs, which often describe the dragon as a holy or noble image. For example, when distinguishing between social classes, the Vietnamese often say, "Dragon eggs hatch into dragons, and the little ones hatch into little ones." To a certain extent, the Vietnamese dragon is different from the dragons of Northeast Asian countries, which have been feminized due to the tradition of respecting women in Vietnamese social history. On the other hand, the Vietnamese dragon absorbs the Southern element in harmony with the Naga snake god in Southeast Asian culture. The history of Central and Southern Vietnam has strong interactions with the “Indianized” countries in history, therefore, the dragon image is closely associated with the Naga snake symbol originating from Brahmanism.