THE FIERCE pig-like creature -- flying with two sets of flaming wings, thrusting his curvy iron horn before him -- pursued the museum director up and down, and finally cornered him in his own bedroom in Kongju, Korea. His fright was mixed with interest. He had never seen such a creature before.

At that, the director woke up with many misgivings about his day's work -- a small archeological site nearby where water was seeping into the excavation. Even so, he went out to dig. Work hadn't been under way long before he heard an unexpected sound.

The shovels had hit brick, a patterned brick, indicating an important tomb.

When the director pushed through the last barrier, there stood the fierce creature of his dream, identical from his wings to his scalloped horn, grinning his "I'm going to eat you up" smile.

The tomb guardian, made of painted hornblende and iron, had protected the tomb of King Munyong, Songsanni, at South Ch'ungchong Province since the early 6th century A.D.

The find was enormously important, not only because such a creature had never been found before in Korea, but because it was the first Paekche (a kingdom from 18 B.C. to 660 A.D.) tomb to be found undisturbed.

The stone plaques marked it as the tombs of the king and queen who reigned from 501 to 523. The main chamber and south passageway were built of bricks pressed with lotus patterns. The tomb confirmed the record of the Samguk Sagi history, which said the king was as brave and peaceful as his burial name, Munyong, implied. He had been with a great diplomat that in life he was called the Great General of Peaceful East. He was especially noted for his negotiations with China. His tomb guardian is like many in the medieval mythological menagerie of China called the tien lu (heavenly deer).

This story was told by Han Byong Sam, director of the National Museum of Kyongju, Korea. Dr. Han is in Washington to help install the most important exhibitions of Korean art ever to leave Korea. The last Korean show in Washington was in the 1950s, before most of the major excavations.

Eight objects from the Munyong tomb -- bricks, a silver cup, jade and gold ornaments, silver bracelets, gold earrings, gold crown ornaments and a gold hairpin shaped like a ginkgo leaf -- are among the 354 precious artworks from Korea to be displayed at the Smithsonian's Museum of Natural History/Museum of Man beginning July 15 and continuing through Sept. 30. The exhibit is in the new Thomas Evans Gallery, the Constitution Avenue space redesigned to accommodate big changing exhibitions. The Smithsonian's coordinator is Chang-su Houchins, who acted as Dr. Han's interpreter in a recent interview.

According to the catalogue, "5,000 Years of Korean Art," the Koreans say their nation, which they call Choson, was founded by Tangun, the son of a female bear, and an early man called a Yemeak, himself the offspring of a deity, more than 2,000 years before Christ.

Whatever their origins, archeologists have found paleolithic sites dating back 20,000 to 30,000 years in Korea. The oldest piece in the show is a comb-pattern pottery jar dating from 3000 B.C. By 1000 B.C. Koreans were making "plain coarse pottery" and excellent stone implements.

Six hundred years before Christ, in a great cultural blooming time, the Koreans learned how to make bronze and build monuments to their dead.

The monuments were great cists, cairns, dolmens -- huge stones megaliths. During the country's Three Kingdoms period (1st century B.C. to 7th century A.D.), the nation extended into Manchuria in the north and the Han river in the south.

Buddhism was introduced into the country by a Chinese monk named Sundo, who came to Koguryo with his scriptures and statuettes. Koguryo is famous for its murals inspired by Chinese Buddhist images. And soon the Buddhist cultures spread throughout the land. The Buddhists, however, never succeeded in eliminating the old shamanistic beliefs in good and evil spirits. These ancient traditions have modified not only Buddhism, but other religions practiced in Korea, making them particularly Korean.

Buddhism "caused entire granite mountains, such as the Namsan near Kyongju, and granite caves, such as the famous Sokkuram, to come to life with carved and free-standing effigies of The Enlightened One and other deities of Mahayana Buddhism," the catalogue notes.

Han pointed out, "Because so many of the great temples are actually part of the mountains and the mountain caves, and because both sides were careful not to bomb known sites, very little destruction to the important art works was caused by the 1950s' Korean War, though of course some things were lost in moves to places of safe keeping."

Knowledge of Korean art has lagged behind that of Japanese and Chinese work. Though the early tombs were filled with gold, bronze and ceramics, it is said that Korea's early masons were such good artisans that the tombs resisted grave robbers for more than 1,000 years.

Han said, "Too often people speak of Korean art as unstudied or a part of Japanese art. There are many points of similarity with both Chinese and Japanese art, but Korean art keeps its own strong individuality."

Han quotes Choi Sunu, director of the Korean National Museum at Seoul, who says poetically that Chinese artwork is like an actress -- dramatic, showy. Japanese art is like a geisha girl -- delicate, charming. Korean art is like a wife/mother -- earthy, warm. "The Korean bronze statues, for instance," Han said, "are easily recognized because they are softer, not so stern, in the facial features, in the drapery, than the Chinese. The figures look like Korean people, not Chinese."

Perhaps the friendliness of Korean art made its folk art popular early. The Korean artists were not afraid to use humor as a basic material. One of the most charming pieces is a vessel in the shape of a warrior, an ash-glazed stoneware piece from the Gold Bell Tomb, Kyongju. The warrior has a wonderful hat and a determined, pointed nose. His horse looks rightly apprehensive, as he should with those horseshoes shaped like women's pumps. The vessel was filled through a cup-shaped protuberance on the horse's back and poured out the spout sticking in his breast.

Some of the 54 paintings reflect this same sense of the ridiculous, especially "Women on Tano Day," showing a ritual washing. The women, half nude, are bathing in a stream while two monks hiding behind a rock are enjoying the sights. According to the catalogue, the painter, Sin Yunbok, lost his job because of his fondness for erotica. The painting, ink and colors on paper, is one of five album leaves dated 1758.

The great Korean celadon ceramics -- gray-green, iron-oxide, celadon glaze applied to porcelain clay bodies -- have been greatly admired since the turn of this century and are probably the best known of all Korean art. Some 100 pieces of ceramics are in the exhibit.

"Celadon was made in Korea in the 9th century [Koryo Dynasty, 918-1312], but celadons didn't appear in Japan until the 15th century. We believe the Japanese captured Korean potters and brought them to Japan to make celadon," Han said.

Most of the celadons were flower vases, bowls, cups and small dishes, wine pots and bottles and water droppers. The same techniques were also used for incense burners, roof tiles, pillows, Buddhist water sprinklers, oil bottles and toilet cases. All types can be seen in the Natural History exhibition. Several blue and white porcelain objects from the 15th through the 18 centuries are also shown in the exhibit.

The incense burner with cover, a celadon-glazed porcelain ware with open work and incised decoration from the early 12th century, is especially lovely. The incense would seep through the spherical ball. The base is a trompe l'oeil of chrysanthemum leaves. The feet are small rabbits, giving you the feeling the incense burner may run away in all directions.

The early celadon ceramics were incised, stamped or molded. About 1150, inlay and underglaze copper an iron painting began. In the 12th century, Korean potters invented the celadon inlay technique using contrasting materials, especially silver, but sometimes other metals.

In the Smithsonian exhibition, the showiest objects are the 30-odd gold crowns and crown ornaments from the Old Silla (5th-6th century A.D.), used in the shamanistic rituals. A gold and glass crown was found in the Gold Bell Tomb at Kyongju. The central uprights are like a tree with curving pieces on the side, which from some points look like upright animals. From the gold structure hang two pendants decorated with hollow gold balls and blue glass beads. Another crown, from the Heavenly Horse tomb, is of gold and jade, also from Kyongju. A gold cap is decorated with fish scales, animal shapes and latticework, all made of gold.

The first important excavations were made by Japanese archeologists during the early 1920s, when the country was occupied by Japan. The work continued until the war in the 1940s, to be resumed in the 1960s. Major tombs were excavated in 1971, 1973 and 1974.

Dr. Hans own town of Kyongju is a veritable outdoor museum of ancient artifacts. "We have regulations forbidding buildings on the old sites," he said. "But it is considered bad luck to build over a grave, and as soon as some artifact is found, the builders move to another place."

An enormous number of objects have been found, according to Han. "In 1975 and 1976 we excavated an artificial lake, Anap-chi, with three islands in the grounds of a palace of the Silla period at Kyongju.The lake had been double the size we thought. And we found 20,000 objects in it."

In the Smithsonian exhibit from this site are bronze and gold objects including several gilt bronze Bodhisattvas (one whose "essence is enlightenment"), two gilt bronze and copper dragon heads, believed to have been armrest ornaments, bronze snuffers, as well as gray ceramic roof tiles ornamented with flowers, and a roof end tile with monster masks to guard the end of rafters against evil spirits.

When more bronzes are uncovered, Han believes the Korean bronzes will rival the Chinese.

The most important work in the exhibit, according to Han, is the seated Maitreya (Buddha of the Future) figure in meditation, the foot resting on a lotus blossom. "The figure is almost exactly the same," Han said, "as the greatest Japanese treasure, the wooden Buddha in Kyoto."

The exhibit includes 26 Buddhist sculptures.

A Bhaisajyaguru (Buddha of Medicine) gilt bronze figure of the Silla period standing holding a medicine bowl is thought to be more like Indian counterparts. The round-faced figure with his curly topknot hat (or is it hair?) has a serene, rather self-important face as befits his status as The Doctor Is Now In. Another Bhaisajyaguru figure has rosebud lips and a voluptuous figure. An Amitabha (Pure Land Buddha) is made of solid gold.

A wonderful Buddha Triad, cast in a single piece of gilt bronze, shows the Buddha making the sign of turning the wheel, seated on a lotus flower with his Bodhisattvas flanking him. It is similar, according to the catalogue, to one in the Tokyo National Museum "and reflects the close stylistic ties between the two countries during the 8th century."

Not all the bronze pieces are Buddhas. The kundika is a bronze water vessel inlaid with silver from the 11th-12th century. The long-neck, double-spout shape comes from India by way of China.Some think the inlaid bronzes inspired inlaid celadons. A gilt bronze finial in the shape of a dragon's head concealed a pulley inside his chin to hoist a banner. Not all the Buddhas are bronze. One cast iron Buddha weighs two tons. Others are of granite.

The magnificent collection is making its last of eight stops in the United States here after being organized by the Asian Art Museum in San Francisco with the National Museum of Korea. The National History museum is scheduling a series of Korean cultural events in conjunction with the exhibit.