Main •
Lee Dong-wook as Lee Yeon :The titular
gumiho (nine-tailed fox). Former mountain spirit and guardian of
Baekdudaegan, lover of Ah-eum / Ji-ah and half-brother of Lee Rang. He carries out missions from the Afterlife Immigration Office while searching for the reincarnation of Ah-eum. He encountered several look-alikes of Ah-eum, but none bore the fox bead. He saved Ji-ah when she was young, but she does not have the fox bead, making Yeon believe that she is not the reincarnation of Ah-eum. Later in the series, it is revealed that Ji-ah is indeed the reincarnation of Ah-eum. Her fox bead appeared when Lee Yeon saved her from falling from a building. His weakness is the evening primrose that grows above tombs. •
Jo Bo-ah as Nam Ji-ah / Yi Ah-eum / Imoogi • Park Da-yeon as young Ji-ah / Ah-eum :Nam Ji-ah is a 30-year producer at TVC Station. She is the reincarnation of Lee Yeon's past lover, Yi Ah-eum, the 7th daughter of the King of Joseon, whom he exiled. To save her father, who was
possessed by the Imoogi, she allowed the Imoogi to take her instead, promising to take him to Yeon. She then asked Lee Yeon to kill her so that she could protect him from sacrificing himself. After reincarnating as Nam Ji-ah, she is often seen to have double personalities, which is later revealed to be the part of the Imoogi that survived inside of her. Imoogi used her to threaten Lee Yeon in order to have his body. When she tried to sacrifice herself again to protect Yeon from Imoogi, she was stopped by him and allowed Imoogi to take over his body instead. •
Kim Bum as Lee Rang •
Lee Joo-won as young Lee Rang :A half-blood gumiho and Lee Yeon's younger brother, who seeks revenge on his brother by creating mischief. He intentionally causes harm to humans, which causes trouble to Yeon in turn. He hides his caring nature while harboring a deep grudge for his brother. As a child, he was abandoned by his human mother in the Forest of the
Hungry Ghosts. There, he was attacked by hungry ghosts but was saved by Yeon. He followed his brother to the mountain to start anew and lived happily. But when Ah-eum died, Yeon left Baekdudaegan and abdicated his status as the mountain spirit, leaving Rang alone on the mountain, thus causing the growing hatred for Lee Yeon.
Supporting Mythical beings around Lee Yeon •
Kim Jung-nan as Taluipa :Younger sister of
King Yeomra (supreme ruler of the
underworld), and wife of Hyunuiong. She works at the Afterlife Immigration Office, managing the list of dead souls and gives missions to Lee Yeon. She appears to be cold-hearted but has a strict motherly affection for Yeon, who calls her "Granny" in return. She had a son named Bok-gil who could not undergo reincarnation because he committed suicide by jumping into the Samdo River, as a result of her decision to kill his beloved woman infected with the plague. •
Ahn Gil-kang as Hyunuiong :The gatekeeper of Samdo River, the husband of Taluipa and father of Bok-gil. He also works at the Afterlife Immigration Office and briefs dead souls before entering the underworld. He appears to be both obedient and scared of his wife, who "wooed" him in debased parodies of the folktale
Fairy and the Woodcutter and the Korean drama ''
I'm Sorry, I Love You, before committing bossam'' (forcefully marrying him). •
Hwang Hee as Goo Shin-joo :Lee Yeon's loyal subject and friend, also a gumiho. After having bewitched innocent humans to lose their minds in revenge for his sisters, who were killed by human traps, he fled from the former mountain spirit he served to save his life and ended up at Lee Yeon's forest. He was saved by Lee Yeon, who refused to return him to the mountain spirit and since then decided to dedicate his life to him. In the present day, he is a veterinarian who can speak to animals using his magic necklace. He liked Ki Yu-ri from the first time he met her, when she stole his necklace. •
Kim Soo-jin as
Snail Bride / Bok Hye-ja :Owner of the "Snail Bride", a traditional Korean cuisine restaurant where Lee Yeon and Nam Ji-ah's team at TVC Station usually dines in. She's a widow living for hundreds of years already, and is knowledgeable about all the supernatural beings in the world. Her husband was devoured by a tiger through the Spirit of Darkness's trick on someone's greatest fear.
Mythical beings around Lee Rang •
Kim Yong-ji as Ki Yu-ri :Lee Rang's loyal accomplice, a young gumiho from Russia. Five years before the current events, she was saved by Rang from a zoo where she was being maltreated. As her way of payment for saving her life, she eagerly carries out Rang's orders in causing trouble to his enemies. She assumed the identity of the 24-year-old director of Moze Department Store who died while trekking in Nepal. •
Lee Tae-ri as adult
Imoogi / Lee Ryong / Terry • Kim Tae-yul as young Imoogi :A serpent beast in human form, the nemesis of Lee Yeon, who has the power to read others' minds. He was born in
Silla as the 9th son of a
Jingol family, but with physical deformities similar to a snake. His father considered him a monster that needed to be got rid off, and on the advice of a midwife who stopped him for fear the child might be cursed, on a certain day of a
leap month of a
leap year, he was sealed up in a cave used to dispose of plague victims, who promptly devoured the child and transformed him into a white serpent. To escape his dark prison (similar to Korean folklore) he waited beneath the waters for 1,000 years to become a
dragon but was disqualified after a human spotted him as he was about to ascend, turning him into an Imoogi. The first person to treat the Imoogi with kindness was Taluipa & Hyunuiong's son Bok-gil, but not wanting to see his happiness, he infected Bok-gil's lover with the plague, causing him to lose his mind and commit suicide at Samdo River. To satisfy his ambition of becoming a mountain spirit, he then possesses the body of the King of Joseon, Ah-eum's father, as a host. To save her father, Ah-eum allowed the Imoogi to possess her body for him to meet Yeon, who killed him while inside of Ah-eum. Centuries later, he eventually washed up at Eohwa Island
in 1959 during Typhoon Sarah as an "impure thing" and was thrown into a covered well. To be resurrected, the island's shaman lured young women as human sacrifice every
15th day of the 7th lunar month; and despite the failed sacrifice of Ji-ah, she was eventually reborn (with the help of Kwon Hae-ryong and Lee Rang) through her spilled blood, all but one of the residents of Eohwa Island, and inadvertently Lee Yeon's powers. As a child, the Imoogi sucks his babysitters' life force (turning them into mummified corpses) as his meal to be fully grown in a short period of time, and as an adult, assumes the physical appearance of Bok-gil. His new goal now is to possess the body of Lee Yeon and be the new mountain spirit of Baekdudaegan, with Nam Ji-ah as his bride. With the help of his servant, the CEO at TVC Station disguised himself as Terry, an intern in Ji-ah's team at TVC Station. Similar to Korean folklore, his weakness is horse blood, and the method of his resurrection is the same method to fully vanquish him. • Jung Si-yul as Kim Soo-oh :A young boy adopted by Lee Rang. In his previous life, he was Geomdung, the black puppy raised by Lee Rang, which was given to him by his brother Lee Yeon, and he died due to a fire set by humans in the mountains 600 years ago. Soo-oh first appeared as a kid at the park, met by Lee Yeon. Later on, Soo-oh immediately recognized Lee Rang at the sidewalk, though Lee Rang initially did not reciprocate. Soo-oh found the Eyebrows of the Tiger in the form of glasses, which can make its wearer see the past life of another. Rang retrieved it from him and, upon wearing it, discovered Soo-oh is indeed the reincarnation of his beloved Geomdung. Later on, he was saved by Rang from his abusive step-father.
People around Nam Ji-ah •
Um Hyo-sup as Kwon Hae-ryong :The CEO of TVC Station, who is secretly the Imoogi's mysterious servant. He served during the reign of Ah-eum's father. As he sacrificed his wife and children to the Imoogi in exchange for extending his life, he is described as a living corpse, since he prolonged his life for centuries by consuming human spirits trapped in
bladder cherries (in Korean folklore, lured snakes). He also saved Lee Rang's life after he was supposedly killed by Yeon, thereby making Rang indebted to him. He, as a man in a navy blue suit with the criminal branding "Seogyeong" ("Western Capital", which was
Pyongyang during the
Goryeo period; the punishment rendered towards surviving rebels involved in
Myocheong's Rebellion, whose headquarters were located at said area) on his forehead, caused the car accident of Nam Ji-ah's parents. He eventually betrays the Imoogi, and is, in turn, killed by him while possessing Ji-ah's body. •
Jung Yi-seo as Kim Sae-rom :A writer at TVC Station and Ji-ah's teammate. In her past life, she was Ah-eum's handmaiden during her exile, and she was killed by her mistress while possessed by the Imoogi. •
Kim Kang-min as Pyo Jae-hwan :A PD assistant at TVC Station and Ji-ah's teammate. In his past life, he was Ah-eum's personal eunuch during her exile, and he was killed by his mistress while possessed by the Imoogi. • Joo Suk-tae as Choi Tae-suk :Team leader of Nam Ji-ah, Kim Sae-rom and Pyo Jae-hwan, who woos Bok Hye-ja. He is revealed to be the reincarnation of Bok Hye-ja's deceased husband. •
Kim Hee-jung as Lee Young-sun :Nam Ji-ah's mother, who is a doctor. She went missing after the Yeou Gogae accident 20 years ago and was revealed to have been turned into a bladder cherry along with her husband. She and her husband were eventually released from her otherworldly prison through Lee Yeon & Lee Rang's help. • Song Young-kyu as Nam Jong-soo :Nam Ji-ah's father is a professor. He went missing since the Yeou Gogae accident 20 years ago and was revealed to have been turned into a bladder cherry along with his wife. He and his wife were eventually released from her otherworldly prison through Lee Yeon & Lee Rang's help.
Other mythical beings •
Shim So-young as the Spirit of Darkness, the Imoogi's partner who preys on someone's greatest fear. She appears as a lady peddler in a green outfit, targeting her victims by giving away bottled juice for free, then showing them a door that will open towards their greatest fear with the victims hearing the "Doorkeeper Game" from
Ganggangsullae, and as they engross themselves with their own fears they slowly die. She has been part of Korean urban legends, but rarely could anyone even recall her name in the present day (which turns out to be her own greatest fear: the fear of being forgotten). Among her victims were Bok Hye-ja's husband and, through the Imoogi's bidding, Lee Rang, Nam Ji-ah & Lee Yeon as well. Ultimately, she was killed by Yeon after he tricked her into entering his subconscious and taunted her with her greatest fear (Ep. 8 & 9). •
Woo Hyun as the
Jangseung of Yeou Gogae, who appears as a mysterious old one-eyed drunkard. He first appeared at a bus stop where Nam Ji-ah was supposed to board a bus that went into a fatal accident later. He annoyingly grabbed Ji-ah's leg to stop her from boarding, which also meant saving her life. She volunteered to carry him on her back going home, but asked to be dropped off by the side of the road. Later on, he involuntarily gave Rang the lead in obtaining the Eyebrows of the Tiger (Ep. 1 & 5). •
Son Woo-hyeon as Jung Hyun-woo, a security staff at TVC station whose true form is a Bulgasari (Ep. 2, 9 & 16). •
Lee Kyu-hyung as Governor /
Moon Bear, a former mountain spirit and best friend of Lee Yeon (Ep. 6 & 15). He currently resides at a Korean folk village with other supernatural spirits under his care, playing their parts entertaining tourists. He owned the Mirror of the Moon, one of the four gems of the four mountain spirits. He provided a crucial lead on the disappearance of Nam Ji-ah's parents, revealing that Ji-ah was, in fact, the actual target in the first place. • Lim Ki-hong as King
Odo Jeollyun, the 10th and last Afterlife judge who is in charge of the Darkness Hell as well as of reincarnation. He would occasionally leave his post to stay in the human world. He is first seen as a mysterious fortune teller with white eyes, who trades powerful objects for the most precious thing in someone's life. Through him, Lee Rang traded his brother Lee Yeon in exchange for the Eyebrows of the Tiger. In turn, Nam Ji-ah traded her fox bead to redeem Lee Yeon (Ep. 6 & 16). • Lee Jung-min as the bride whose true form is a gumiho. On her wedding day, Lee Yeon pursued her to execute the punishment by death for the crimes she committed against humanity (Ep. 1).
Eohwa Island •
Kim Young-sun as a shaman who attempted to sacrifice Nam Ji-ah to the Imoogi. She was the one who discovered the Imoogi when he was swept into Eohwa Island and was hidden inside a covered well for safekeeping. She then distributed shamanist folk paintings of the Imoogi disguised as the
Dragon King towards the island's fishing community, while also luring young women into the island to be sacrificed for Imoogi's resurrection. In return for her loyalty, she was bestowed long life and youth, until Lee Yeon killed her while rescuing Ji-ah from being sacrificed to the Imoogi (Ep. 2–3). • Do Yun-jin as Seo Pyung-hee, daughter of Seo Ki-chang. She is the only one who did not mysteriously disappear on the island; however, she is the one who cursed her father's crew-mates with the help of the shaman & Lee Rang (Ep. 2–4). • Maeng Bong-hak as Seo Ki-chang, father of Seo Pyung-hee, who was murdered and eaten by his crewmates when they were lost at sea (Ep. 2–3). • Ji Heon-il as Jin-sik, a fisherman (Ep. 2–3). • Jang Yong-chul as a fisherman (Ep. 2–3). • Keum Dong-hyun as a fisherman (Ep. 2–3). • Kim Gui-seon as fishing boat captain (Ep. 2–3). • Kim Sun-yool as a mountain spirit bound to a tree. She relayed what scant information she knew about the Imoogi, and was later released by Ji-ah (Ep. 2–3). • Joo Boo-jin as an elderly woman (Ep. 2–3). • Park Seung-tae as an elderly woman (Ep. 2–3).
Special appearances • Lee Taek-geun as the groom of the disguised gumiho bride (Ep. 1). • Son Dong-hwa as the groom next door (Ep. 1). •
Chu Ye-jin as Jung Soo-young, a 17-year-old student who was the only survivor of a deadly bus accident at Yeou Gogae, later morphed into Lee Rang as her true form. The real Soo-young was killed (eaten) by Rang (Ep. 1). • Jang Won-hyung as Baek Si-woo, the detective who investigated the bus accident at Yeou Gogae that killed 5 people (Ep. 1). • Jang Eui-don as a bus passenger who died in the accident, husband (Ep. 1). • Yoon Tae-hee as a bus passenger who died in the accident, wife (Ep. 1). • Kim Hwan-young as the son of the bus passengers. He met Lee Rang at a wishing fountain at Moze Department Store before (Ep. 1). • Yu Jun-won, a family member of one of the deceased bus passengers (Ep. 1). • Choi Sung-woong as funeral hall security (Ep. 1). • Choi Seung-il as father of the real Ki Yu-ri (Ep. 4). • Oh Jung-won as the mother of the real Ki Yu-ri (Ep. 4). • Lee Ye-bit as Min-seo, a child ghost (Ep. 4–5). • Jung Ah-young as Yeon-seo, a child ghost (Ep. 4–5). • Park No-shik as Min-seo & Yeon-seo's father. He was away at work as a truck driver when his daughters died, allegedly by his "negligence" (Ep. 5). • Kim Nak-gyoon as Min-seo & Yeon-seo's uncle. It was revealed that he sexually molested his nieces while drunk, and while escaping, accidentally fell off the veranda to their deaths (Ep. 5). • Jang Young-hyeon as a watch salesman at Brennetano (Ep. 5). • Jo Hyun-im as Imoogi's first babysitter (Ep. 5). • Seo Jin-won as Seo Hwan-ho, a baseball player who maltreated a puppy (Ep. 5). • No Seong-eun as No Hae-sung, a baseball player who maltreated a puppy (Ep. 5). • Han Chang-hun as Han Tae-soo, a baseball player who maltreated a puppy (Ep. 5). • Shin Ji-Yeon as Imoogi's final babysitter, his last meal before becoming an adult (Ep. 7). • Park Su-yeon as Lee Rang's mother, who abandoned him. She resented having a child with a gumiho (Ep. 7–8). •
Sunwoo Jae-duk as the King of Joseon, Ah-eum's father, the first host body of the Imoogi. He made a deal with the Imoogi to possess him in exchange for Ah-eum escaping her fate as the Imoogi's sacrifice (Ep. 8). • Kim Young-sun as Psychiatrist Choi, a friend of Nam Ji-ah's mom. She facilitated Ji-ah's hypnotherapy session when she was 9 years old, which revealed that a part of the Imoogi survived despite Ah-eum's death and reincarnation as Ji-ah (Ep. 8). • Kim Hyo-myung as Kim Soo-oh's stepfather. Lee Rang led him to be turned into a cherry bladder for Kwon Hae-ryong's consumption (Ep. 11). ==Release==