Eunha is a baby Dokkaebi with tremendous magical energy with great proficiency in shapeshifting.
Eunha was born under a red full moon. The elders were in awe and claimed she'd turn out to be the Dokkaebi king. The Dokkaebi king was the hero who led the Dokkaebi and founded their own nation in the past. The king had powerful magical energy that rivaled the sages, and had the strength to move mountains. It's said the Dokkaebi king had tremendous magical energy. For Dokkaebi, the amount of magical energy they have is determined at birth. Therefore, everyone had high expectations for Eunha becoming the next Dokkaebi king. This news spread across the Dokkaebi village, and even those that weren't Dokkaebi started to take interest in Eunha.
At some point, evil spirits started to appear in the world of the living. They began stealing magical energy from magical beings and these instances began to happen quite often. It's unknown why the evil spirits emerged in the world of the living, but there is a rumor that a certain entity is working behind the scenes. There was no way the evil spirits would let Eunha's magical energy be. They tracked Eunha down and attacked the Dokkaebi village.
For the peace and joyful Dokkaebi disliking conflict, the evil spirits were too powerful. Eunha safely escaped the village because of her mother, but it was no easy feat losing the evil spirits chasing after her because of her vast magical energy. In the end, Eunha's mother hid her daughter in the village's alleyway. Then she promised her daughter she'd return before leaving Eunha. For months Eunha waited for her mother to return, and spent a long time being lonely. Eunha is deeply scarred from spending a long time in hiding and being alone from a young age. She's cowardly and weary of dealing with others.
The gourd used by Eunha has been passed down for generations. It's the shapeshifting Infinite Change. This magical item received great power from the sages long ago. Eunha's vast magical energy allows her to wield the item better than any other Dokkaebi. While she's using it, she can completely change her appearance and hide her great pool of magical energy as well.