Two animals, a tiger and a bear, desired to become human, so they prayed daily to Hwanung. Hwanung heard their prayers and appeared to them. He instructed them to stay in a cave for one hundred days, eating only mugwort and garlic. The tiger was impatient and failed the test, but the bear persevered and was transformed into a beautiful woman. Hwanung married her, and she bore him a son, Tangun Wanggeom, who would later found the first Korean kingdom.
The son (Korean: seo-ja, meaning second or lower son) of Hwanin, he descended from heaven to Mount T'aebaek and founded the City of the Gods beneath a sacred tree. From this city he ruled the people and instructed them in agriculture, medicine, justice and other matters. He was hailed by the people as "King of Heaven."