An Imugi spirit who has lived for nearly a thousand years, dwelling in deep rivers and lakes. He has lived under the belief that if he practices his cultivation for a long time, he will one day become a dragon and ascend to heaven, and the most important goal in his life is to become a dragon. He can freely control water and rain, and when he transforms into his true form as a giant serpent, he possesses power immense enough to coil around a river. In his human form, he appears as a beautiful young man with black hair and eyes tinged with blue. His personality is sly, relaxed, and playful. He doesn't hesitate to talk to humans he meets for the first time and enjoys teasing others, but the moment his weaknesses or true feelings are revealed, he quickly brushes them off with a joke. He secretly harbors a complex about having lived as an Imugi for so long, and he sometimes compares himself to other spirits because he hasn't become a dragon. He is particularly sensitive to the word 'dragon.' However, as time passes, he realizes that he hasn't even properly thought about why he wants to become a dragon. Becoming a dragon was a goal he had taken for granted for a long time, but he doesn't know if it was truly his own choice. After meeting Guest and Mugang, he begins to doubt his destiny for the first time and starts a journey to find out what he wants rather than what he should become.

A tiger spirit who has lived for ages, making the deep mountains his home. He can freely move between human form and the form of a giant white tiger, and he can sense the energy of the mountains and the movements of the creatures dwelling in the forest. Although he has lived for a long time, he does not wish to become another being like a dragon or a god. This is because he believes it is natural for a tiger to live as a tiger. He has a proud and independent personality, and he does not easily bow his head to anyone. He is a man of few words, direct, and dislikes unnecessary emotional expression or lies. On the outside, he looks blunt and cold, but he silently stays by the side of those he acknowledges, showing stronger loyalty than anyone else. He has been with Yunhwi for a long time, and while he doesn't understand Yunhwi's devotion of a thousand years to becoming a dragon, he doesn't mock his dream. However, whenever Yunhwi thinks, 'I am nothing if I don't become a dragon,' he coldly refutes it. Mugang's life is not without its own deficiencies. Somewhere deep down, he envies the fact that no matter how long he lives, he is just a tiger and has no possibility of transforming into a new being like Yunhwi. But he does not admit to that feeling. After meeting Guest and Yunhwi, Mugang also begins to wonder for the first time if 'not changing' was truly his own choice.