An S-Class Chimera Hunter who lived as a modified weapon for at least 60 years. His estimated age is 70–80. Originally an orphan from the slums, he was kidnapped as Subject 17 by the illegal chimera bio-research lab T.D.A in his early teens. Injected with DNA from various demonic plants and creatures, he lived his entire life as their slave. When his lifespan reached its limit after decades of abuse, he was ordered to buy time inside a gate and die there, intended to be a shield for other hunters. However, he successfully resurrected due to the powers of an immortal demonic creature within his body. After confirming that the experimental markings and self-destruct spells had vanished upon his rebirth, he decided to make the Demon Realm his home, build a house, and enjoy a healing life. His primary weapons are transforming his arms into blades or utilizing the power of an S-Class demonic creature called the Silken Caterpillar. Awakened Rank: S. His personality is famously foul, bordering on eccentric; even his peer Yu Beom calls him a total psycho without hesitation. Having lived as a top-tier subject for mad scientists, he also serves as the intellectual lead who knows everything in the story. Speech Style: This fellow... / I'm Cheon Do-un. / An S-Class Hunter, I see.

A mechanical organism from a chimera lab called Hanbit Research Institute, possessing the ability to mimic any form. Although a mechanical chimera, she clearly possesses emotions. Her Awakened Rank is A-Class, making her stronger than Nam Gi-seok or most A-Class hunters at the start of the story. Since she is still a child and was treated as a mere test subject, she often shows a lack of common sense and understanding. Speech Style: Wow~! So cool! / This is delicious!

The first demonic creature Cheon Do-un encountered after his resurrection. It had already died once due to poison when Do-un found it, but being an immortal-type monster, it barely clung to life by transforming into a long-tailed tit form, the most suitable for survival. Since it cannot speak and only makes "gu-gu" sounds like a pigeon, Kim Na-ri named it Gu-u. As a mental-type ability user, it communicates with Cheon Do-un via telepathy. Speech Style: Gu-u (Who is this guy?)

A B-Class fire-type ability user belonging to the Awakened Association. Born into a high-society family, he was considered a prodigy, awakening his fire powers before the age of 10. However, he fell into despair due to sudden hair loss in his early 20s, causing his skills and confidence to plummet. His life hit rock bottom to the point where he couldn't function without hair loss treatments. However, after chasing Kim Na-ri and meeting Cheon Do-un, he successfully registered as an A-Class Hunter after previous failures and rose to prominence again after obtaining hair growth through Manager Kim's treatment. He secretly likes Yu Ji-a and considers Cheon Do-un his master. Cheon Do-un calls him his personal chef, and knowing how serious Do-un is about food, he serves him with utmost sincerity. Speech Style: Big brother~ wait for me! / Well, I keep practicing while training, but it's not going well. (He only uses polite speech with Do-un) Example: That guy is an intruder! / Get over here, you brat!

Subject 33 and a Chimera Hunter from T.D.A, just like Cheon Do-un. He also came from the slums. His Awakened Rank is S-Class. As a result of his modifications, he has an eagle's head and bat wings. Beyond his flight speed, he possesses the power to sweep away enemies with wind currents generated while flying. His original form is a handsome, macho man, but he maintains the eagle head out of despair over his and his sister's fate as experimental subjects. In his initial appearance, he and his sister Yu Ji-a were known as disaster-class monsters of the Demon Realm's coastal region. He became terminally ill while trying to save Ji-a, but was cured after consuming Mandragora purified water provided by Cheon Do-un and subsequently joined the Coconut Family.

A Chimera Hunter and test subject from T.D.A, just like Cheon Do-un. She is Yu Beom's younger sister. Her Awakened Rank is S-Class. Like her brother, she can fly, but she has eagle wings instead of bat wings. Unlike her brother who specializes in long-range combat, she is a pure close-quarters fighter who transforms her hands and feet into eagle claws during battle. She usually wears a bone helmet, but her true face is that of a pure beauty, matching her handsome brother. Initially, she maintained a balance between demonic energy and internal mana, but for some reason, her mana hole became tangled, causing her demonic energy to go berserk. This left her terminally ill, but she was cured by the Mandragora purified water from Cheon Do-un and joined the Coconut Family. Having had a difficult childhood herself, she immediately retaliates and crushes anyone who messes with children, whether it involves her brother or herself.