what can you tell about their tradition?
The "druk" of Bhutanese mythology, has been the national symbol of Bhutan since long before the establishment of government in 1907
National symbols of Bhutan
The "druk" (Dzongkha: འབྲུག་; Wylie:" 'brug"), or "thunder dragon" of Bhutanese mythology, has been the national symbol of Bhutan since long before the establishment of government in 1907. Since the seventeenth century, Bhutan's self-designation has been "Drukyul" ("Land of the Thunder Dragon"), or "Dru-gäkhap" ("Kingdom of the Thunder Dragon"). The Druk is heavily associated with the dominant Drukpa sect of Buddhism, the state religion under Bhutan's dual system of government. 
what is the name of national flag of bhutan The flag features a dragon from Bhutanese mythology were any changes made to the flag? Yes, the second version of the national flag was developed in 1956 what other national symbols does this flag's country has? National emblem, national anthem, and the mythical "druk" thunder featured in all three what is its anthem? "Druk Tsendhen"
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National symbols of Bhutan [SEP] Druk tradition
The "druk" (Dzongkha: འབྲུག་; Wylie:" 'brug"), or "thunder dragon" of Bhutanese mythology, has been the national symbol of Bhutan since long before the establishment of government in 1907. Since the seventeenth century, Bhutan's self-designation has been "Drukyul" ("Land of the Thunder Dragon"), or "Dru-gäkhap" ("Kingdom of the Thunder Dragon"). The Druk is heavily associated with the dominant Drukpa sect of Buddhism, the state religion under Bhutan's dual system of government. This sect was founded in western Tibet by Drogon Tsangpa Gyare Yeshe Dorje (1161–1211), who with his disciples witnessed nine dragons roaring out of the earth and into the skies, as flowers rained down everywhere.