This is the Characters page for the Sweet Home (2017) webcomic on Webtoon and the miniseries based on it. Currently under construction.
WARNING: Due to the nature of the series, all spoilers are unmarked. You Have Been Warned!
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Higher Floor Group
Cha Hyun-soo/Hyun
Click here to see him as a monster
Played by: Song Kang
The main protagonist of the comic, a Hikikomori who moved into an apartment building just before monsters appeared.
- And Then John Was a Zombie: Hyun begins to resist his monster infection less and less, for the sake of having the strength to protect everyone else. In the climax of the webtoon, he finally gives into his monster infection and turns to defeat the Final Boss. Although the same thing happens in the miniseries, Mr. Han gives him a Cooldown Hug that turns Hyun back into a human, albeit at the cost of the inventor's life.
- Better to Die than Be Killed: In the earlier chapters, Hyun keeps thinking about ending it all so he can at least die a human. He's forced into heroism before he can do so and later decides that he wants to live after all.
- Big Brother Instinct: Towards Sook and Yeong. He had a younger sister, but she tragically died in a car accident alongside their parents.
- Broken Ace: Flashbacks show that he was a very popular and skillful student, until something happened...
- Bullying a Dragon:
- After all the abuse Hyun suffered at the hands of his former friends and realizing that his family never truly cared about his wellbeing, he adopts a fairly jaded and suicidal personality. However, upon seeing his bully attempting to bait another student into committing suicide, he finally snaps and almost successfully kills his bully by pushing him into the road instead.]]
- In the miniseries, Ui-myeong shoots Yu-ri and Sang-wook and ridicules Hyun for crying after killing whom he thought was Sun-young. He also opens fire on the Green Home residents, most of whom Hyun had come to regard as his friends. As expected, he changes into his monster form not soon after.
- Character Development: Undergoes this throughout the story, turning from a cynical jerk who only wants to commit suicide to a heroic individual that wants to save as many people as possible.
- Dare to Be Badass: Initially, Hyun is a depressed teenager who only wants to kill himself as soon as possible. However, when Mr. Han asks him if he wants to save Sook-yeong and Yeong-sook, Hyun immediately says yes.
- Dangerous Forbidden Technique: Any time Hyun uses his monster powers, he risks changing into a monster permanently and giving control over to his monster side.
- Dark and Troubled Past: Hyun was a dedicated and well-rounded student and a great dude in general...until his classmates and peers started to bully and socially exclude him for pretty much no reason. To make matters worse, his parents betrayed his trust and did little to intervene because the kid who started it all was the son of Hyun's father boss. Hyun's life spiraled out of control from there, causing him to become anti-social, bitter and mentally unstable.
- Death Seeker: At first, he planned on committing suicide after seeing a movie (or attending a gaming event in the miniseries) he had been waiting for, feeling he had no reason to live after the death of his family. His character development changes him into someone who desperately wants to survive the apocalypse and live.
- Earn Your Happy Ending: After dealing with so much trauma throughout much of his late adolescence (from dealing with his bully to losing his parents and younger sister in an accident to fighting monsters and becoming one himself), Hyun is able to find the right people whom he calls his family: the surviving residents of Green Home Apartment.
- Friend to All Children: What kickstarts Hyun's character development is his determination to rescue Sook and Yeong after their father dies, to the point that he is willing to cross multiple monster-infested floors just to get them to safety.
- Healing Factor: As a result of being infected, Hyun has a rapid healing factor that enables him to get up close and personal with the other monsters.
- Heroic Willpower: So far, Hyun is the only person able to fight off his impending monsterization with sheer willpower alone.
- Hikikomori: Has become one long before the story began. He grows out of it by force when the monsters appear.
- Important Haircut: In Episode 8. After a pep talk from Eun-yu, he finally decides to let go of his past and starts being more sure of himself.
- He grows it back out after his Unexplained Recovery in Season 2.
- Jerkass: At the start of the story, he was more depressed about his inheritance being so small than the fact that his entire family died. He grows out of this when the monsters start appearing.
- Jerkass Has a Point: While his antagonistic attitude towards his family is pretty awful in the prologue-especially since his mom was trying to be nice — it's at least partially understandable, given that his parents did next to nothing to help him when he was being bullied.
- Jerk with a Heart of Gold: Even at his worst, Hyun still had the potential to be good person.
- The Main Characters Do Everything: Justified, as Hyun is the only main character that has some control over his monsterization, he's much stronger than everyone else, and is thus forced to be the muscle of the group.
- Mercy Kill: He mercy kills a dying soldier in the first episode of the second season. He also apparently mercy kills Yi-kyung at the end of Season 2 by dropping her down a hole after she gets monsterized.
- Mercy Kill Arrangement: Early on in the miniseries, he asks Ji-su to kill him before he can turn and hurt anybody.
- Naked on Arrival: In the final chapter, Hyun came out of his cocoon as a naked, evolved, and humanoid monster.
- Nice Guy: Flashbacks showed that he used to be this but something happened that made him a hikikomori. Apparently, a bully who was the son of his father's boss betrayed his trust, beat him to an inch of his life, and turned Hyun's friends against him. His family's lack of support only worsened things, to the point that Hyun thought suicide was the only option left for him.
- Parental Substitute: Becomes one to Ah-yi, Yi-kyung's daughter in Season 2.
- Post-Final Boss: Hyun forfeits his humanity and manifests his full monster form to defeat monster Joon Shin. But this causes his Superpowered Evil Side to take him over to good, forcing Hyuk to sacrifice himself to allow Jisu and Wook to escape.
- Pretty Boy: Is repeatedly called one in the miniseries by multiple characters.
- One-Winged Angel: During a solar eclipse in the miniseries, Hyun-su's monsterization literally transforms one of his arms into a set of serrated wings that he uses to kill Ui-myung's host. Mr. Han manages to prevent him from harming the rest of the survivors ... but at the cost of his own life.
- Power at a Price: The more Hyun uses his powers, the more likely he'll become a monster. In chapter 138, he finally gives into his monsterization for the power to kill Joon Shin and protect his friends.
- Ship Tease: With Ji-su in the webtoon and Eun-yu in the miniseries.
- Shock Stick: Hyun's main weapon is a broken mop handle with a knife attached to it, which Mr. Han later upgrades into being able to conduct electricity. In the webtoon, it eventually becomes a part of his monster form.
- Shrinking Violet: At the start of the story, Hyun has a tendency to hunch in on himself, speaks quietly enough that he is often asked to repeat what he just said, and avoids eye contact with people.
- Sole Survivor: His entire family died in a car accident when their car crashed into a truck.
- Spoiled Brat / Used to Be a Sweet Kid: Earlier on in the story, he is presented as a greedy, self-absorbed, and disrespectful brat. At his own family's funeral, he lashes out in front of everyone present and angrily asks how he is meant to live off of the meager savings they have left behind. Deconstructed later on with The Reveal that although Hyun was being bullied and beaten regularly by the son of his father's boss, his family simply turned a blind eye for fear of Hyun's father losing his job if they spoke up. When Hyun finally fights back by pushing his bully into oncoming traffic, his father is fired and Hyun is isolated further in school. At one point, he also overhears his parents and little sister blaming him for his own abuse and outright calling him a burden. In short, Hyun only became a brat when he realized that no one really loved him and his efforts at standing up for himself were futile.
- Superpowered Evil Side: All the infected have this, but Hyun's is very eager to play mind games with him.
- Super-Strength: The more his infection progresses, the stronger he gets. By the end, he can break the floor by casually jumping and throw his spear with enough force to punch a hole in a wall.
- Supporting Protagonist: Both the webcomic and the miniseries occasionally take a backseat from Hyun's story to focus more on what the other survivors are up to.
- Tender Tears: Hyun cries multiple times in the miniseries - during his attempted suicide, when he is unable to stop Jae-heon from being killed, seeing Mr. Han's dead body, and after having to Mercy Kill a suffering soldier and Yi-kyung.
- Trauma-Induced Amnesia: In the miniseries, the shock of transforming into a monster before turning back into a human is too much for him and he loses most of his memories. Despite this, he tears up at the sight of Mr. Han's corpse and even says that his heart feels like it's breaking.
- Unexplained Recovery: Ui-myeong, possessing Sang-wook's body, petrifies Hyun and leaves him to die early in Season 2 of the miniseries. He later appears shortly after Yi-kyung gives birth with no explanation as to how he was un-petrified.
Yoon Ji-soo/Ji-su
Played by: Park Gyu-young
A bass player who lived in the apartment directly above Hyun's.
- Adaptation Dye-Job: In the webtoon, Ji-su has bright brown hair. In the mini-series, her hair is black, but the lower half is dyed pink, befitting her "rocker" personality.
- Adaptation Relationship Overhaul: In the webtoon, there was a strong amount of Ship Tease between her and Hyun; in the miniseries, no such relationship exists beyond them being allies and later friends.
- Anger Born of Worry: As part of their Ship Tease, she is shown worrying for Jae-heon, only to snap at him for provoking The Beefcake when he reveals himself to be alive.
- Batter Up!: Ji-su has a metal bat as her weapon of choice. It later gets spikes after Du-sik fixes it up.
- Big Damn Heroes: She saves Yeong-su after the government bombs the stadium at the cost of her own life.
- Cartwright Curse: The source of her angst in Episode 9, considering how her ex-boyfriend committed suicide and Jae-heon dies after professing his love for her.
- Celebrity Resemblance: Ji-su is stated by both Hyuk and Hyun to resemble Maria from the in-universe cartoon Maria from the Sky. Hyuk even states her personality is similar to Maria's.
- Death by Adaptation: She apparently dies in the miniseries after being crushed by falling concrete after the government bombs the stadium in Season 2, but the camera cuts away before we see her die, leaving her fate unknown.
- Determinator: No matter the situation, Ji-su absolutely refuses to give up. Even if she's going to die tomorrow, she'll still fight to survive today.
- Hidden Heart of Gold: Ji-su pretends to be more cold-hearted than she is to survive, but she's far too kind to actually do anything brutal.
- Inelegant Blubbering: When she sees Jae-heon's grave, Ji-su is reduced to crying and screaming as she remembers the last time she ever saw him.
- Love Hurts: Ji-su's boyfriend committed suicide and Hyun urns into a monster in front of her to save her life in the last few chapters. As for the miniseries, let's not forget Jae-heon, who confesses that he wants to be with her...only to die right after while protecting the other residents.
- Mercy Kill Arrangement: In the miniseries, Ji-su agrees to kill Hyun if ever he turns, only if he does the same for her. She almost goes through with it in Episode 10, only to be stopped by Eun-yu.
- Morality Chain: Ji-su is able to calm Hyun down, preventing his monster side from taking over.
- Nice Girl: She's one of the nobler survivors, completely willing to risk her neck for people she's just met. In the miniseries, she's constantly looking out for the little kids and hands Jin-ok a protein bar she'd been saving for herself when the older woman is too depressed over her daughter's death to eat.
- Nice Job Breaking It, Hero:
- In the webtoon, by dousing Myeong-Ja's infected cocoon with gasoline, she allowed Yi-hyun's violent personality to set it on fire, which inadvertently enraged every single monster in the area surrounding the building.
- Early on in the miniseries, she and Jae-heon create a massive SOS banner, which they then hang from the rooftop. Come Episode 8, Yi-kyung orders Sang-wook and Hyun to take it down for fear of attracting the military's attention. This leads to Hyun being unable to warn the survivors in time of the infected security guard's existence, which results in Jae-heon's death.
- Red Oni, Blue Oni: She's the fiery, impulsive, and action-oriented red to Jaeheon's calmer and quieter blue.
- Ruptured Appendix: Happens to her in the miniseries. When the plan to get proper medical supplies for her goes south, Ji-su has to undergo emergency surgery from Eun-hyuk without any anesthesia. To make matters worse, although Eun-hyuk is a medical student, he's also one who has never done surgery before.
- Ship Tease: With Hyun in the webtoon, and Jae-heon in the miniseries.
- Suicide is Shameful: Ji-su hates the idea of suicide after her ex-boyfriend hung himself. Thus, she'll do everything to survive and refuses to let anyone kill themselves as well.
- Tragic Keepsake:
- Her bass is her boyfriend's. He left it to her after committing suicide.
- In the miniseries, Eun-yu gives her the broken shard of Jae-heon's katana after his death and it becomes her main weapon from then on.
- Traumatic Haircut: Her hair becomes shoulder-length in the miniseries after a monster grabs on to her hair in the car park and Jae-heon has no choice but to slice it off.
- Unstoppable Rage: As the webtoon goes on, she becomes more and more protective of Hyun and loses her temper if he's threatened.
- Vitriolic Best Buds: With Eun-yu in the miniseries. The 'best buds' part may be a bit of a stretch, considering how acidic their behavior towards each other can get, but when Jae-heon dies, Eun-yu is the only person shown actually comforting her, first with chocolate, then with somewhat kind words.
Han Du-sik/Du-sik
Played by: Kim Sang-ho
The sole occupant of Room 1408. He has limited mobility due to having lost part of a leg (or having lost feeling in both legs in the miniseries), but is pretty good at weaponry crafting.
- Better to Die than Be Killed: He tells Hyun that the last bullet in his gun is reserved for him, seeing as he doesn't want to die of old age, be killed by the monsters, or turn into one. In the mini-series, he ends up using it on the Spider Monster after it almost eats Sook-yeong.
- Cooldown Hug: Administers one to Hyun-su in the miniseries after his monsterization worsens during an eclipse. It costs him his life.
- Cool Uncle: Acts as this towards Sook-yeong and Yeong-sook.
- Died in Your Arms Tonight: In the webtoon, Du-sik dies in Hyun's arms after his flame bomb clears the garage of monsters. The miniseries inverts this a bit by having him hold Hyun to prevent him from hurting the other residents and gets impaled by the latter's One-Winged Angel form in the process.
- The Engineer: He's in charge of making all the weapons and technology the group uses. He reveals his skill is the result of too much time on his hands.
- Establishing Character Moment: Saving Hyun from the Eyeball Monster and asking him to rescue Sook-yeong and Yeong-sook from their apartment.
- Foil: To Hyun. Both were people who "lost" their loved ones (Dusik having being abandoned by his wife with their son), Hyun's family dying in a car crash), both were something of geeks(however the generational gap stops them from fanboying over the same stuff), and both were infected. However Dusik is consistently a great fellow, while Hyun was an complete asshat before he started mellowing out again. Dusik was physically disabled, while Hyun was not. Dusik was also much Older and Wiser than Hyun.
- Handicapped Badass: Du-sik might be wheelchair-bound, but his skill in weapon crafting is top-notch enough that Eun-hyuk gives the go-ahead for Hyun to retrieve him from his apartment—a mission that involves going through fourteen monster-infested floors.
- Heroic Sacrifice: In both the webtoon and the miniseries, albeit in different ways. In the webtoon, after realizing his monsterization gave him a leg, he throws a huge flame bomb to kill all the monsters attempting to enter from the garage at the cost of his life. In the show, he dies by giving Hyun-su a Cooldown Hug while the latter is in a fully berserk monster mode.
- MacGyvering: He manages to create a homemade rifle out of a hollowed-out crutch and an air compressor. He also creates/modifies weapons for several others, including a spiked/bladed bat, a riot shield, and an electrified spear.
- Nice Guy: Despite food being scarce, Du-sik is more than happy to share it with the survivors.
- No Good Deed Goes Unpunished: The webtoon reveals that in the past, he saved a child's life at the cost of his foot, which resulted in his wife and child leaving him because he couldn't find work.
- Throwing Off the Disability: Seeing as monsterization gives a human what they most desire, Du-sik regains the use of his legs in both adaptations. In the webtoon, he is able to regrow one of his legs. In the latter, he is able to walk again and manages to keep Hyun-su from going on a wild rampage.
Jung Jae-heon/Jay-hun
Played by: Kim Nam-hee
A Korean teacher and devout Christian who has lived at Green Home for over a year.
- Amazon Chaser: According to Jae-heon's actor, he started to have feelings for Ji-su when she charged The Beefcake first and gave it a Groin Attack to boot.
- Anguished Declaration of Love: Unsure of whether or not he will survive a battle in the miniseries, he confesses to Ji-su and tells her he wants to be with her.
- An Arm and a Leg: The monsterized Mr. Kim slices off his left arm in the miniseries.
- Badass Preacher: While not a pastor per se, he is a devout Christian who isn't afraid to share his faith with others and kills the most monsters out of the main characters.
- Beware the Nice Ones: He looks like a harmless, slightly geeky, teetotaling proselytizer, but is quite prolific with a sword. In the webtoon he was also a kumdo expert, explaining his proficiency with weapons.
- Heroic Sacrifice: In the miniseries, he holds off the monsterized Mr. Kim in the elevator while bleeding out from a missing arm and orders Eun-hyuk to throw a Molotov cocktail and burn the both of them.
- Katanas Are Just Better: He has a katana as his weapon.
- Nice Guy: In his first appearance, he explains Myeong-sook's behavior to an understandably creeped-out Ji-su and even apologizes for being too forward. In the webtoon, he doesn't shun Hyun for being infected—a trait that carries over into the miniseries. It's also implied that he was the one who told the other residents why Sang-wook has such a big vendetta against Choi Yoon-jae. He's also a devout Christian but very tolerant of other people's beliefs. When he dies, all of the survivors present are in tears, including Eun-hyuk.
- Odd Friendship: With Sang-wook in the miniseries. After Jae-heon prevents a heavily injured Sang-wook from leaving the compound, the gangster warms up to him considerably and even punches Seung-wan in the face after the latter shoves an injured Jae-heon into a display case. At the start of Episode 9, Sang-wook is shown mourning his death and even pours soju all over Jae-heon's grave as a way of paying his final respects.
- Recovered Alcoholic: In the miniseries.
- Red Oni, Blue Oni: He's the calmer, more level-headed blue to Ji-su's fiery and emotional red.
- Religious Bruiser: Prior to each fight, he yells out verses and prays for strength. In one of his conversations with Sang-wook in the miniseries, he reveals that religion helped him overcome his alcoholism.
- Sacrificial Lion: He is the first sympathetic character killed by the monsters to show that Anyone Can Die.
Kim Su-yeong/Kim Sook and Kim Yeong-su/Kim Yeong
Played by: Heo Yool (Sook-yeong), Choi Go (Yeong-sook)
Two children living in an apartment below Dusik's. Sook is 9 and Yeong is 6.
- Adaptational Badass: Su-yeong in the miniseries is more matured. Even after the Spider Monster almost eats her, Su-yeong readily throws a Molotov Cocktail at it when it injures Mr. Han.
- Big Sister Instinct: Su-yeong is extremely protective of Yeong-su.
- Death of a Child: Su-yeong is killed by Jae-hwan early in Season 2.
- Girlish Pigtails: Su-yeong.
- Harmful to Minors: They quite literally watched their dad fall out of a 12-story building and splatter onto the pavement.
- Theme Twin Naming: In the miniseries, of the gendered variant.
Lim Myeong-ja/Lim Myeong-sook
Played by: Lee Bong-ryun
A middle-aged woman who also appears to be infected by the virus. Not the most sane, given her past...
- Adaptational Name Change: Her name is Myeong-Suk in the miniseries.
- Deader than Dead: In the webtoon, her monster form eventually becomes a cocoon, only to get incinerated by Yi-hyun, therefore discarding any chance of her evolving. Although Ui-myeong leaves her alone in the miniseries, the building itself collapsed after being shot at by the military, leaving her fate unknown. She later reappears in Season 2, but is rammed by a military vehicle and almost incinerated until the Blind Monster intervenes, leaving her fate unknown yet again.
- Fingore: In the miniseries, she almost succumbs to monsterization while cooking dinner and ends up chopping off her fingers as a result.
- Hidden Depths: She's actually fully aware that her "baby" is a hallucination and she's pushing around an empty stroller, but she keeps up the façade as she would rather live in a hallucination than accept the truth.
- Living MacGuffin: Yi-hyun burns her cocoon after Ji-su soaked it in gasoline in a failed attempt to destroy it, which was enough to aggravate all the surrounding monsters and kick-start the climax.
- Mama Bear: Due to losing her baby, she's very protective of all children, especially Sook-yeong and Yeong-sook.
- Mercy Kill Arrangement: In the miniseries, she asks Mr. Han to kill her if she turns. However, since her monster form is ultimately a peaceful one, he cannot bring himself to do it and is even seen talking to her as he awaits his own transformation.
- Naked on Arrival: Like all newly reborn human monsters, her re-introduction in Season 2 is in the nude.
- Outliving One's Offspring: Prior to the start of the series, her baby died when the stroller rolled out into the middle of the street.
Ahn Gil-seop/Seop
Played by: Kim Kap-soo
An old man who decides to venture out with his caregiver Yu-ri instead of staying put and dying in his room.
- Big Damn Heroes: Twice. He saves the main characters from being killed in the car park with an improvised flamethrower. Later on, he draws The Beefcake's attention away from a badly-dazed Hyun by throwing Molotov Cocktails at it and pushes Hyun out of the way when the monster attempts to crush them both.
- Blood from the Mouth: Happens to him in the miniseries when he is about to let himself be crushed by The Beefcake.
- Cool Old Guy: After emerging from his unit, he's not afraid of putting his life on the line to help others, and he's pretty well-prepared at defending himself with his crossbow. He helps Hyun and Sang-wook when they're in a pickle to defeat the Tentacles Monster (webtoon)/the Long-Armed Monster (miniseries). In the miniseries, he also becomes a grandfather figure to Sook-yeong and Yeong-sook, has a motorcycle lying outside that he occasionally peeps at in hopes of being able to ride it soon, and burns down some monsters in the carpark with a flamethrower.
- Do Not Go Gentle: Even though he's terminally ill, he wishes to kill as many monsters as possible before that happens.
- Heroic Sacrifice: He pushes Hyun out of the way of The Beefcake’s punches and gets crushed in his place. Subverted in the miniseries where Yi-kyung suddenly returns with a firetruck to mow down the sucker down.
- Nice Guy: Although she shows shades of being The Gadfly early on towards Hyun and Yu-ri, he's definitely one of the nicest characters in the series and it shows.
- He eats dinner with Hyun and Sang-wook when the rest of the survivors shun them, and tells them about himself to make the pair loosen up.
- He sternly, yet kindly reprimands Seung-wan when the younger man understandably panics and reminds him to take good care of himself.
- The main reason he wanted to leave his apartment in the first place? He believes that Yu-ri deserves more than taking care of him until he passes.
- Old Soldier: It's implied that he is a retired soldier and is completely unafraid of dying if it means saving everyone else.
- Passed in Their Sleep: How he dies in the miniseries. Sook-yeong goes to wake him for breakfast and finds that she can't. While it's a sad moment for all the survivors, his death here is definitely more peaceful than how he goes out in the webtoon.
Park Yu-ri/Yuri
Played by: Go Yoon-jung
The senior caregiver for Mr. Ahn. She helps to patch up the survivors and suffers from asthma.
- Beware the Nice Ones: In the miniseries, mild-mannered Yu-ri is ultimately the one who kills the rapist when he starts beating up Ji-su.
- Death by Adaptation: Dies alongside Sang-wook in the miniseries from gunshot wounds before they could drive off to find more asthma medication for her.]]
- Ethereal White Dress: She appears in a vision to Ui-myeong/Sang-wook in the first episode of Season 2, causing him to crash his getaway vehicle.
- Heroic BSoD: After stabbing Kap-soo in the miniseries, the poor girl can only mumble "I killed a person" when Sang-wook finds her. As the pair lie dying from their gunshot wounds, she repeats the statement and voices her fear that it'll be the last thought she has before passing.
- Holding Hands: Right before he dies, Sang-wook takes her hand so neither of them are alone in their final moments, and only then does she close her eyes for good.
- The Medic: Helps tend to the survivors' wounds, due to her past medical knowledge.
- Official Couple: With Sang-wook in the webtoon,and teased in the miniseries.
Lower Floor Group
Lee Eun-yu/Eun
Played by: Go Min-si
A spirited teenager and Eun-hyuk's younger sister.
- Aerosol Flamethrower: Begins using this as her weapon towards the end of the webtoon.
- Adaptational Jerkass: Likes to sass at her fellow survivors in the miniseries.
- Bratty Teenage Daughter: Although she isn't as angsty as the standard archetype in the miniseries, she's usually shown with a pair of headphones on and definitely loves making things harder for everyone present, but most especially her brother.
- Establishing Character Moment: In the miniseries, Hyun-su sees her performing ballet on the rooftop as he contemplates suicide. She offers him a cigarette, and when he declines, bluntly tells him to look for another place to kill himself as committing suicide at Green Home will only cause more trouble for the residents.
- Fiery Redhead: In the webtoon. She's spunky and willing to tell Hyuk off when she thinks he's being a jerk. In the series, her hair is a natural shade of black, but she's no less sharp.
- Jerk with a Heart of Gold: She's the resident Snark Knight and has zero tact, but she does have a kinder side underneath the bitchiness.
- Important Haircut: About halfway through Season 2, she cuts her hair short in the ensuing year-long Time Skip.
- It's All My Fault: She blames herself for her and Eun-hyuk's parents' deaths because she forced them to come to her ballet recital, which has also driven a wedge between them.
- Pinky Swear: Asks Hyun-su to make one with her in the miniseries, the contents of which she keeps secret from him. It's later revealed that she made him promise to survive, not just for them, but also for himself.
- Say My Name: In the miniseries, she starts screaming for her brother when she realizes he was lying about coming back.
- Searching for the Lost Relative: She believes Eun-hyuk is still alive and continues to search for him. She is proven right at the end of Season 2, when Eun-hyuk is reborn as a monster.
- Ship Tease: With Hyun-su in the miniseries.
- The Snark Knight: A world-weary character who snarks indiscriminately? Absolutely fits.
- Took a Level in Badass: In Season 2, she becomes an Action Survivor who goes out hunting for supplies by herself and can hold her own in a fight.
- Vitriolic Best Buds: With Ji-su. The two of them throw hateful comments at each other on every given opportunity, but when Jae-heon dies and Ji-su breaks down, it's Eun-yu who seeks her out and talks some sense into her. She's also shown crying when Ji-su passes out from shock on the operating table, as well as when Ji-su is apparently killed by falling debris in Season 2.
Lee Eun-hyuk/Hyuk
Played by: Lee Do-hyun
A relatively plain teen and Eun-yu's older brother.
- Ambiguous Disorder: Hyuk is incredibly smart and is usually able to understand people very well, but he has No Social Skills, his filter is nonexistent, he can easily get distracted, and he has a very rigid and overly-pragmatic (and sometimes plain weird) way of thinking.
- Big Brother Instinct: He's very protective of Eun-yu and tells Sang-wook to hide the fact that he's infected so as not to worry her.
- Came Back Wrong: He is reborn as a monster in the ending of Season 2.
- Fatal Family Photo: He secretly takes his sister's last photo of them as a family and is shown looking at it in his final scene, which also doubles as his death scene.
- The Friend Nobody Likes: Fellow survivors acknowledge him as a core member of the group but are quick to call him out for his apparent lack of empathy towards others.
- The Gadfly: A Socratic version, Hyuk will ask questions or say cold things to test the people around him or motivate them to do the right thing, but very few people end up liking him as a result.
- Go Out with a Smile: In the miniseries. Even as the building crumbles down, one of the very last shots we see of Eun-hyuk is him smiling, seeing as he knows his sister and their friends will be safe.
- Heroic Sacrifice: At the end of Season 1, he decides to stay behind once he gets his Deadly Nosebleed, knowing that his monsterfication is not far off.
- Hidden Heart of Gold: Eun-hyuk often acts as if he's completely detached from the situation at hand, but anyone can tell that he's actually far more emotional and caring than he lets on. It's revealed that the cold and pragmatic attitude he puts up is to prevent anybody from panicking and, more often than not, to anger people into doing the right thing.
- Hidden in Plain Sight: Eun-hyuk is seen early in Season 2 when the party returns to the Green Home apartments - but in his cocoon, which he emerges out of in the ending of Season 2.
- The Leader: He takes this role in the miniseries.
- Naked on Arrival: Like all monsters, he emerges out of his cocoon naked at the end of Season 2.
- Otaku: He's a big anime and video games fan, and regularly talks about fighting the monsters in RPG terms. Eun-yu even states he had figurines before the crisis occurred.
- Mirror Character: In the comics, he is very much this to Hyun. Both are young men who (surprisingly) went through some hardships in life, were big nerds (even liked the same stuff !), both were less than ideal individuals who were nonetheless good where it mattered, and both were monster infected who used their respective transformations to protect others.
- No Social Skills: Deconstructed. Prior to the outbreak, he was isolated by his classmates and never learned tactfulness. As a result, survivors are quick to question his motives and is heavily mistrusted, thanks to his pragmatic way of thinking.
- Not So Stoic: In the miniseries, Eun-hyuk's calm facade actually breaks multiple times.
- While cleaning Min-ju's blood off his glasses, he's visibly shaken at having been unable to prevent the deaths of two people, even though he couldn't possibly have done anything to save them.
- He's clearly teary-eyed when Jae-heon asks him to torch the elevator with him and the monsterized Mr. Kim inside.
- He screams when Sun-young is killed in front of him and falls to his knees in front of her corpse.
- Secret Test of Character: When Eun-hyuk sends Hyun and Sang-Wook to get Du-sik and the kids, he asks Hyun to focus on Du-sik, even at the price of Sook-yeong and Yeong-sook's lives ... but only to see if Hyun is the type of person to sacrifice children.
- Smart People Wear Glasses: He's the smartest person amongst the survivors and wears glasses.
- Those Two Guys: He develops this dynamic with his right hand man, Sang-wook. In the miniseries, Sang-wook's role is relegated to Yi-kyung and she becomes something of a big sister figure/advisor to him instead.
- Uncertain Doom: At the end of the first season, he's shown to be having a massive nosebleed right as the apartment building is getting decimated by the military outside. Season 2 shows that he is still alive - but has been reborn (presumably) as a monster.
- Vitriolic Best Buds: With Hyun in the webtoon.
Pyeon Sang-wook/Wook
Played by: Lee Jin-wook
An intimidating man who isn't as frightening as he appears.
- Adaptational Jerkass: Ties up a man in his apartment and tortures him in the miniseries (although once said man's deeds are revealed, his actions are proven to be justified). He's also more distant towards his fellow survivors.
- Bruiser with a Soft Center: He's one of the group's heaviest hitters, but he's especially gentle with Yu-ri and the kids. In the miniseries, he's especially protective of Yook-seong and even tells him to close his eyes so he doesn't have to watch Sang-wook kill a man.
- Came Back Wrong: Jung Ui-myeong (actually Sang-won) possesses his body at the end of Season 1 and for the remainder of Season 2.
- Comfort the Dying: Even though he's dying himself in the miniseries, Sang-wook uses his final moments to reassure Yu-ri, insisting that even though she killed Kap-soo the rapist, it doesn't matter because the man no longer had any humanity left in him. He also makes the effort to intertwine their fingers so Yu-ri doesn't have to be die frightened. Subverted in the sense that he doesn't actually die, as his body is then possessed by Ui-myeong.
- Death by Adaptation: In the miniseries, he dies with Yu-ri before they can drive off to find more asthma medication for her. However, he shows up again at the very end, albeit with his body having been taken over by the Puppeteer Parasite monster.
- Draft Dodging: In the miniseries, two gangsters call him out for holding them at gunpoint with the safety on and he responds that he didn't serve in the militarynote . Instead, he knocks them out with good ol' Pistol-Whipping.
- Expy: In the webtoon—give him a sport coat and he's basically Kazuma Kiryu, down to the personality traits.
- Face of a Thug: Bulky and intimidating to the point that Eun-yu sometimes calls him 'Mr. Mobster', but he's definitely an ally.
- Good Is Not Soft: Sang-wook will retaliate if he feels his or the others' lives are in danger, but if you earn his respect, he'll show you Undying Loyalty.
- Gotta Kill Them All: Sang-wook's personal goal in the webtoon is to kill every monster in the apartment complex for safety reasons.
- Hates Being Touched: In the miniseries, he chokes Yu-ri upon waking when she makes the mistake of treating him while he's unconscious. He then tells her never to touch him. Averted later on when she reprimands him for his devil-may-care approach towards living and he asks her to help him clean his wounds.
- Heroic Build: Sang-wook is very muscular and strongly cares about everyone in the group.
- Made of Iron: In the miniseries. The only thing that downs him for good is when Ui-myeong shoots at him and Yu-ri when they try to escape.
- The Starving Monster takes a huge chunk out of his shoulder and even then, he has more than enough strength to throw her through a wall and kick her repeatedly until she stays down.
- He also gets hit in the head multiple times with a hammer and even though he passes out from having acquired multiple wounds by that point, he's more or less fine the next time he wakes up.
- When The Beefcake swats their van aside, Sang-wook recovers fast enough that he's able to cut an unconscious Yu-ri out of her seat and, despite bleeding copiously himself, is perfectly capable of carrying her to safety before the car explodes.
- Muscles Are Meaningful: When Baek Ho-yeon challenges Sang-wook to a fight, Sang-wook easily beats him because he's 20 kg heavier.
- Kill Tally: Sang-wook keeps track of each monster he kills with a marker tally on his arm.
- Police Brutality: He used to be part of the police force, only to be let go when he beat up a suspect to the point of nearly killing him.
- Ship Tease: With Yu-ri in the miniseries. He quits smoking when he finds out she has asthma and willingly lets himself be treated by her. He also sees a vision of her at the beginning of Season 2, which causes him to crash his getaway vehicle.
- Averted in the webtoon, where they're an Official Couple instead.
- Those Two Guys: He develops this dynamic with Eun-hyuk over the course of the story. In the miniseries, he forms this dynamic with Jung Jae-heon instead, even going so far as to tell Jae-heon a bit about his past.
- Undying Loyalty: He may be willing to question Eun-hyuk's motives, but he will still follow his orders without reservations.
- Younger Than He Looks: Yu-ri thought he was in his 40s when he's only 32.
Ryu Jae-hwan/Jay
Played by: Lee Joon-woo
A young man whose biggest concern was not being able to do his skin care routine.
- Attention Whore: His monster form in the webtoon - it must be validated of its beauty every few seconds. Given a Shout-Out in the miniseries when he monsterizes in Season 2, all the while screaming things like "My face is perfect!" and "Am I pretty?"
- Dirty Coward: Refuses to fight the monsterized Mr. Kim and instead barricades himself in his room. Fittingly, he's the first casualty of the Green Home residents when he turns into a monster early in Season 2 in the miniseries.
- Mind Rape: In the webtoon, saying that his monster form isn't beautiful causes Hyun to go down with a massive headache.
- Spared by the Adaptation: Averted. Doesn't succumb to monsterization in Season 1 of the miniseries, but does early in Season 2 and is incinerated by the survivors.
- Would Hurt a Child: He kills Su-yeong during his transformation into a monster.
Noh Byeong-il
Played by: Lim Soo-hyung
- Death by Adaptation: Dies after being gunned down by Ui-myeong in the miniseries.
- Dirty Coward: In the webcomic. He's a little better in the show, albeit he's more of a wannabe tough guy.
- Dying Moment of Awesome: He dies after shielding Hye-in from Ui-myeong's bullets.
- Ship Tease: With Hye-in, multiple times, in the miniseries.
- Time-Passage Beard: Downplayed in that he grows more of a light moustache in the epilogue.
- Will They or Won't They?: With Hye-in. They don't, because he dies.
Son Hye-in/Hyein
Played by: Kim Gook-hee
The local gossip of Green Home apartments, she lives with her Pomeranian dog Bom.
- Adaptational Nice Guy: In the miniseries, she's much less paranoid and harmful towards her fellow survivors.
- Age Lift: Is slightly older in the miniseries and is even called an ahjummanote .
- The Bus Came Back: Bom suddenly returns and helps the remaining survivors find a way out of the underground tunnel network after their escape.
- Evil-Detecting Dog: Her pet dog, Bom, in the miniseries barks at the door Yi-kyung was about to enter so that she can restore power to the building. True enough, that's where the Spider Monster has been lurking all along.
- Heel–Face Door-Slam: She owns up to her mistakes and resolves to become a better person right before she's killed by the flying monster in the comic.
- Jerk with a Heart of Gold: She's gossipy and nosy, but is offended by Seok-hyun's abuse of his wife, is willing to fight the monsters, and gets mad when people treat Hyun-su differently.
- Put on a Bus: In the miniseries, her dog Bom suddenly goes missing and she spends a while trying to find him. She also has barely any screentime in Season 2 before being Killed Offscreen.
- Spared by the Adaptation: In the miniseries, she survives to the point where the survivors get rounded up by the military. She gets Killed Offscreen in Season 2, possibly during the missile attack on the stadium.
- Uncertain Doom: Not her, but Bom - as seen in the first episode of Season 2, during the chaos of the escape from Green Home, Bom escapes and isn't seen again for the remainder of the series.
Kim Seok-hyun/Seok
Played by: Woo Hyun
Seon-yeong's husband. In the miniseries, he owns the convenience store.
- Asshole Victim: No one feels sorry for him when he turns into a monster and his wife is forced to kill him.
- Bald of Evil: Wears a completely unconvincing wig.
- Domestic Abuse: Clearly hostile towards his wife throughout their decades of marriage.
- Hate Sink: Physically and emotionally abusive to his wife, refuses to let the others eat the food in his store despite everything that's happening, wants to kick Hyun-su out immediately...
- Hidden Depths: His interactions with his inner monster heavily imply he is fully aware he is a horrible person and feels a level of remorse over his terrible treatment of his wife. He was however to self-centered and idiotic to change before it was to late.
- Laser-Guided Karma: He immediately wanted to kick Hyun-su out of the apartments after the latter reveals his monsterfication. Not long after, he begins to show signs of monsterfication himself and is locked up with Hyun.
- Nice Job Breaking It, Hero: Raises the building shutter, which lets a monster into the building and kills a survivor, leading to Eun-hyuk and Sang-wook (or Yi-kyung in the miniseries) to risk their lives trying to fend it off.
- Sanity Slippage: Locking him up in a room as an infectee doesn't do wonders for his mental health.
- Tragic Monster: Only in the webtoon. After succumbing to monsterization, he regains a sliver of humanity to express remorse for how he had treated his wife, and allows her to kill him.
Ahn Seon-yeong/Seon
Played by: Kim Hyun
Seok's wife.
- Boom, Headshot!: Gets shot by Joon to make an example out of leaving no potential monster alive to the survivors.
- The Dog Bites Back: Subverted. Tries to kill her husband with a knife after he begins showing symptoms of monsterization but can't bring herself to do the deed. Later double-subverted as she does have to put him down eventually as a monster, but goes into a breakdown after.
- Domestic Abuse: Has taken a lot from her husband since the start of their marriage.
- Dying Declaration of Hate: Calls Jung-seop an "asshole" in the miniseries after he asks for Any Last Words?.
- Tally Marks on the Prison Wall: Keeps track of how many days she's been infected in the miniseries in hopes of becoming a so-called 'special infected' who can resist monsterization after 15 days. She was 10 days in before being murdered by Jung-seop.
Cha Jin-ok
Played by: Kim Hee-jung
A survivor who gave the security guard rotten fish. In the miniseries, it's revealed she's a middle-aged lady originally from Gangnam who runs the apartment's day-care centre. She's looking for her daughter Min-ju who hasn't returned from school during the monsterization outbreak.
- Ascended Extra: In the miniseries. She gets not only a name but much more story.
- Bitch in Sheep's Clothing: Gives the security guard a box of fish that turns out to be rotten with a straight face, even mentioning noblesse oblige
in the miniseries. - Jerk with a Heart of Gold: However, she takes on the responsibility of becoming an adoptive mother of sorts to Yeong-su and Su-yeong.
- No Name Given: In the webtoon. Averted in the miniseries where she introduces herself as Cha Jin-ok.
- Outliving One's Offspring: In the miniseries, Min-ju manages to make her way home but dies at the hands of the Tongue Monster before she could even reach the entrance.
- Parental Substitute: Takes care of Sook-yeong and Yeong-sook in the miniseries and teaches the latter how to read as well. She's seen continuing this role in Season 2.
- Spared by the Adaptation: Although she's the first to discover the security guard's monster form, Jae-heon manages to rescue her due to the warning system and she makes it all the way to encountering the military after escaping Green Home in the miniseries.
- We Hardly Knew Ye: Soon after her introduction in the webtoon, as the first person he sees, the monsterized security guard kills her when he remembers the rotten fish she gave him. Averted by the miniseries, where she survives and becomes a Parental Substitute to Yeong-sook and Sook-yeong.
Kim Ji-eun/Ji-eun
Played by: Jeong Ha-dam
One of the residents of Green Home. A shy, timid person who doesn't talk often.
- Dies Differently in Adaptation: She gets to the second-to-last episode before Jung-seop kills her, whereas in the comic, she's killed by one of the monsters invading the first floor.
- Kill the Cutie: She's one of the nicest and benign characters, and gets brutally shot in the back by Jung-seop when she doesn't make it inside the circle in time.
- Nice Girl: She offers to share her meager meal with Hyun-su and even apologizes for his treatment on the other survivors' behalf.
- Shrinking Violet: Shy and quiet, but kind and caring.
The Criminals
Shin Jung-seop/Joon
Played by: Heo Joon-seok
The leader of a gang of thugs that attacks Green Home.
- Ax-Crazy:
- In the webcomic, Joon Shin is a remorseless mass-murderer who multilates corpses and feeds them to the monsters. He is also implied to be pretty unstable in general, given that he assaults Hyuk for mildy bothering him.
- The live-action series also Implies that he is this. See No Kill like Overkill.
- Big Bad: Becomes this during the climax with his arrival. In the miniseries, he's set up to be this, but is rather quickly killed by Ui-myung.
- Disney Villain Death: In the miniseries he gets unceremoniously thrown off the rooftop by Ui-myung.
- Even Evil Has Loved Ones: It's revealed that after breaking out of prison on the bus, he goes to the house of his family as soon as possible in order to ensure they're safe. Unfortunately, he's too late, and they were slaughtered by a monster before he arrived.
- Fantastic Racism: Absolutely hates monsters and special infected. However, he is still a massive hypocrite about it, see below.
- Final Boss: of Sweet Home, the webcomic.
- Good Scars, Evil Scars: Has one across his left eye (right eye in the miniseries).
- Hate Sink: A murderer and a liar who is willing to sink to any low to survive and has almost no positive traits.
- Hypocrite:
- Hates Special Infected but doesn't hesitate in recruiting them as muscle.
- At the brink of death, monster-hating Joon gives in to monsterization to continue living and becomes the Final Boss.
- Large and in Charge: In the Webcomic. He is among the tallest characters, and is built like a brick wall to boot.
- The Leader: Of the criminals
- Manipulative Bastard: Gets the survivors to do his bidding because they owe him one for killing the Beefcake and promises them a way out with a bus, some food, and power supply in the form of a generator. Also, outright killing him will attract undue attention from the monsters.
- No Kill like Overkill: Stabs a soldier his gang was after repeatedly in the miniseries, slices out his finger in an attempt to open a suitcase with a biometric lock, and after seeing him try to scamper away, shoots him so he's dead for sure.
- The Sociopath: Cruel, ruthless, violent, manipulative and a liar, and completely remorseless about it.
- We Hardly Knew Ye: In the miniseries - he is introduced and killed in the same episode.
Baek Ho-yeon
Played by: Cha Woo-Young
- Arrogant Kung-Fu Guy: Fancies himself as a martial artist. He gets his ass handed over to him by Wook, who has hand-to-hand combat skill due to being an policeman ''and'' is much bigger and heavier than him.
- Out of Focus: The least focused of the criminals.
Lim Hyunshik
A former con-man and the second-in-command of Joon's chain gang.
- Affably Evil: As expected from a con-man.
- The Dragon: To Joon Shin.
- Perpetual Smiler: Always has an shit-eating smirk in his face.
- Token Good Teammate: One of the few members of the chain-gang that is not Ax-Crazy.
Seo Gapsu
A sex offender in Joon Shin's chain gang.
- Ax-Crazy: Just as much, if not more so than Joon and Ihyun. Not only he is a Serial Rapist, he also tried to kill Dusik For the Evulz.
- The Friend Nobody Likes: The other criminals are not too fond of him, and he seems to be at the bottom of the gang's hierarchy.
- Hate Sink: A rapist and killer with no reedeming qualities.
- Serial Rapist: He was in jail for rape, and it is heavily implied to be more than a single instance thereof. In the present, he attempts to rape Hyein.
Ihyun Jo
A convict with a Split Personality. He is infected with the monsterization virus, but due to his condition has complete control over his monster side.
- Ax-Crazy: His monster persona is a cruel and agressive Blood Knight. His "normal" persona is good enough but can switch to the monster one in a second.
- Disability Superpower: His DID allows him to use his monster abilities to their fullest without worrying about turning into a monster for good, as only one of his personalities was compromised and transformed while the other remains unchanged.
- Nice Guy: His human persona. The monster one on the other hand...
Government & Military
Park Chan-young
Played by: Jung Jin-young
A former baseball star, he now serves in the Special Forces collecting and transporting survivors to safety.
- Beauty Is Never Tarnished: Like Yi-kyung, he gets abused in all kinds of ways during the series but heals nicely from his injuries and remains handsome throughout.
- Good Is Not Soft: While he's one of the most morally upright and compassionate characters in the series, he won't hesitate to kill monsters.
- Double Standard Rape: Female on Male: Ha-ni, one of the survivors not taking refuge in the stadium, plans to do this to him even though she ends up not going through with it.
- Nice Guy: One of the more pure-hearted characters of the series despite all the horribleness going on around him.
- Riches to Rags: He was a professional baseball player before the outbreak.
Dr. Lim
Played by: Oh Jin-se
A doctor who works for the government, he later joins the survivors in the stadium to continue his research on monsterization.
- The Alcoholic: Becomes one during the Time Skip in Season 2.
- Fingore: He gets shot in the hand by the Prime Minister in a Jack Bauer Interrogation Technique; a year later, it's shown that it didn't heal properly and he still has some trouble with motor skills in that hand.
- Genius Slob: He was already unkempt looking during his introduction, but he takes it even further in the Time Skip by growing his hair out, drinking rubbing alcohol to get a buzz, and constantly wearing the same ragged and dirty lab coat.
- Mad Scientist: Combined with sociopath - he has no problem with killing and torturing his test subjects, and isn't above using blackmail and emotional manipulation to get what he wants, such as persuading one survivor to poison his mother to see if it induced monsterization.
- Threat Backfire: Even after the Prime Minister shoots him in the hand, he refuses to give up the location of the vaccine. When the PM threatens to kill all the refugees at the stadium if he doesn't tell them, he laughs and says that culling the population occasionally is necessary.
Miniseries-Exclusive Characters
Seo Yi-kyung
Played by: Lee Si-young
A firewoman whose fiancé died under mysterious circumstances.
- The Ace: Naturally, as part of her firefighting background. Holds her own towards the monsters more often than not and often helps Eun-hyuk with strategizing.
- Action Mom: Becomes one in Season 2 to Ah-yi.
- Amazonian Beauty: Spends the first part of episode four crawling around air ducts in a sports bra and short shorts, showing a fairly ripped but still shapely physique.
- Badass in Distress: Ends up trapped by the Spider Monster while trying to restore the apartment's power supply but she gets better later on.
- Beauty Is Never Tarnished: Played with. She gets progressively more beat up over the course of the series, but she's still obviously a very attractive woman. Continued in Season 2, where she goes through all sort of abuse (including getting half her face burned horribly!) but still looks extremely attractive.
- But Now I Must Go: Parts ways with the rest of the survivors to find out what exactly happened to her fiancé on her own. She ends up finding him (or more accurately, his body) in Season 2.
- Decomposite Character: Takes up some of Sang-wook's involvement in his plot, given his background as a former cop.
- Fighting from the Inside: After Ah-yi monsterizes half of her body, she alternates between attacking and holding herself back from attacking Hyun-su.
- Interspecies Romance: Unknown to her, her fiancé Sang-won volunteered himself for experimentation when he began to notice monsterization symptoms. Presumably Ah-yi was conceived during this time, explaining her powers and accelerated birth/growth rate.
- Jack Bauer Interrogation Technique: On the receiving end of this. She ends up giving up the location of the other survivors, but it's part of her plan to get them help. Unfortunately, this doesn't quite work out as she intended.
- Mercy Kill: Hyun-su appears to do this to her by dropping her down a big hole at the end of Season 2.
- Offing the Offspring: Has considered this several times to Ah-yi, but her maternal instinct prevented her from going through with it each time. Unfortunately, Ah-yi can read her thoughts, which fuels her hatred towards humanity.
- Parental Abandonment: Left Ah-yi with Hyun-su shortly after her birth, but came to reclaim her after a year.
- Pregnant Badass: Sun-young urges her to take a pregnancy test. It's positive but it doesn't stop her from her usual ass-kicking. She gives birth during Season 2 to a monster-human hybrid.
Choi Yoon-Jae
Played by: Ko Gun-Han
A man being tortured by Sang-wook for an unknown reason. He's actually a child predator; his most recent victim's father hired Sang-wook to hunt him down.
- Asshole Victim: A child predator.
- Cold-Blooded Torture: On the receiving end of it. And after his child predator status is revealed, it's hard to say he doesn't deserve it.
- Defiant to the End: Even as he's getting his face smashed in, he continues to call Sang-wook a murderer.
- Facial Horror: We get several close-ups of his bloody face as Sang-wook beats him to death.
Jung Ui-myung
Played by: Kim Sung-cheol
A member of Jung-seop's gang that invades Green Home and wreaks havoc there.
He's actually Sang-won, Yi-kyung's fiancé, as well as MH-1, the first test subject before the monsterization outbreak.
- Bait-and-Switch Boss: Jung-seop looks like he's going to be the Final Boss, but Ui-myung kills him effortlessly and becomes the true final antagonist of the series.
- Big Bad
- Body Surf: When he arrives at Green Home, Ui-myung is currently inhabiting the body of one of his former experimenters; Seon-yeong's body was temporarily inhabited by him as well. He then takes over Sang-wook after Hyun-su destroys the Ui-myung body. The ending of season 2 reveals that Ui-myung himself was possessed by Sang-won.
- Composite Character: He's based off Ihyun as someone who retains control over himself despite monsterization and has the webtoon Slime Monster's possession abilities.
- Death Glare: Gives one of the outlaws ogling at Ji-su this after telling him Jung-seop is looking for him, which turns out to be a lie.
- Escaped from the Lab: After volunteering to treat his monsterization, he realizes that he's the monster himself. His monster form leaps into the body of one of the people who was treating him and eventually finds himself discovered by the outlaws.
- Even Evil Has Standards: Talks the outlaw who's about to go after Ji-su out of it and kills Jung-seop for planning to torture Hyun-su.
- Evil Wears Black: Dons a black hoodie jacket after revealing himself to be a monster.
- From Nobody to Nightmare: Starts off as a just another outlaw who then progresses to revealing his true self as an autonomous monster, randomly shooting at the survivors after demonstrating that monsters and humans can't co-exist. Season 2 takes it even further by revealing that he's Sang-won, Yi-kyung's fiancé and the first test subject prior to the monsterization outbreak.
- Healing Factor: Causes Sang-wook's burn scars to disappear after entering his body.
- No Good Deed Goes Unpunished: Sang-won volunteered himself to the government for testing once he started showing symptoms and was tortured brutally For Science!, causing him to escape.
- Patient Zero: Possibly, as he was the first test subject as Sang-won.
- Puppeteer Parasite: Ui-myung/Sang-won's special ability is that he can control other people's bodies, dead or alive.
- Sentient Vehicle: Possesses the armed vehicle that brought the outlaws in after Hyun-su destroys his previously-inhabited body.
- Sole Survivor: Of the burning church that Jung-seop's gang found with everyone else in it dead, despite no trace of a monster attack.
- The Stoic: Speaks with and shows barely any emotions in contrast to the rest of the gang.
- Not So Stoic: In the first episode of Season 2, he freaks out and throws a temper tantrum when Hyun-su drags him back to the research facility he escaped from.
- Transhuman Treachery: Believes himself to be an evolution of humankind as he is able to retain control of himself despite monsterization while still accessing his monster abilities.
- Voice of the Legion: Speaks briefly like this after he shoots the survivors indiscriminately and confronts Hyun-su over showing sympathy towards the survivors.
- Walking Spoiler: He becomes a radically different character shortly after his debut. Season 2 takes it even futher by revealing that he's Sang-won, Yi-kyung's fiancé.
Ah-yi
Played by: Kim Si-a
Yi-kyung's daughter. She's revealed to be a hybrid human-monster like Hyun-su.
- Fetus Terrible: Comes out burned and blackened looking, along with being far more developed than she should be at birth.
- Healing Factor: She is pursued and shot down by a bunch of scavengers, but recovers quickly and monsterizes them.
- Humans Are Bastards: Why she hates humanity, as in her words, they hurt her, reject her, and kill her monster friends.
- Lovecraftian Superpower: She can turn humans into monsters by touching them, as well as being able to control and speak to monsters.
- Parental Abandonment: Abandoned by Yi-kyung immediately after her birth, as Yi-kyung thought she had given birth to a monster. When she appeared to be growing like a regular human girl Yi-kyung took her back from Hyun-su and raised her.
- Patricide: She hates Yi-kyung for abandoning her and thinking she should have never been born, and sets fire to their home in an attempt to kill her. She later monsterizes Yi-kyung, knowing that either Hyun or the military will have to kill her eventually.
- Prophet Eyes: Gets these whenever she's in monster mode.
- Rapid Aging: Yi-kyung gives birth to her after presumably just a few months, and after only a year she already looks like and acts like a young teenager.
Monsters
The Starving Monster
Played by: Park Ah-in
A monster who's very, very hungry. It was once Hyun's next-door neighbour, who's an aspiring celebrity down on her luck and fed up of her strict diet.
- Villainous Glutton: It devours Hyun's food and her pet cat as she begins to undergo monsterization.
The Eyeball Monster
The Blind Monster
- Super-Hearing: Since it doesn't have any eyes.
- Villainous Rescue: It kills Chan-young's superior as he's about to set the newly-resurrected Myeong-ja on fire, albeit unwittingly because he was making too much noise.
The Beefcake
Played by: Dane DiLiegro
A large, smiling, muscular monster obsessed with strength. It wanders the building in search of “protein”
- Berserk Button: Calling it weak. Its normal smile is quickly replaced by a look of absolute fury.
- The Bus Came Back:After being tossed out from the apartment due to Jay-hun's trickery, it spent the majority of the time hunting other monsters outside for "protein", until the time came for the group to head out from their stronghold. Beefcake shows up to ruin the day the moment they peek outside for the first time.
- Catchphrase: "Protein!"
- Monstrous Cannibalism: Is even willing to devour other monsters while it's stuck outside after Jay-hun throws him out of the building.
The Blob Monster
An amorphous monster who can creep through the building ventilation and cracks in the walls. It wishes not to be seen but it finds itself more often than not in the survivors' way.
- Benevolent Monsters: It protects Yeong-sook in the miniseries from being discovered by encasing him in the vents.
- Harmless Villain: It doesn't actively try to go after and murder the survivors compared to other monsters.
- Puppeteer Parasite: Possesses Seon's body in an attempt to disguise itself but everyone sees through the ruse, leading to its death shortly thereafter.
- Tragic Monster: After being incinerated by one of the criminals in the webtoon, it was revealed that he was once a boy named Min who tried to hide himself after his mother was murdered by the Blind Monster. The monster's nature and behaviour came from his desire to not be found by the monster.
Mr. Kim
Click here to see him as a monster
Played by: Shin Moon-sung
The security guard of Green Home Apartments and one of the very first victims of the monsterization outbreak.
- Butt-Monkey: The apartment residents don't get along well with him and always berate him for various reasons. One of them even gave him a box of rotten fish. He's made to do groundskeeping in the weekends as no one's available. Deconstructed as later on his desire stemming from his hatred towards the residents turns him into a formidable monster that resists everyone's attacks and kills several survivors.
- Flies Equals Evil: His face is full of flies in the miniseries.
- Implacable Man: He's invulnerable to most of the survivors' attacks due to his desire to kill everyone in the apartment.
- Made of Iron: In his monster form, his weight was able to exceed the weight limit of the elevator. Most of the survivors' weapons also do jack on him.
- No Name Given: He doesn't have a name in the miniseries.
- The Power of Hate: What accelerates his monsterization, and makes him impenetrable to most of the residents' attacks. In the comic, he even shouts out the related grievance they committed against him before killing said resident.
- Sanity Slippage: As soon as he starts having symptoms of monsterization. In the miniseries he stalks Hyun-su's door creepily after Hyun-su refuses to go with him to finalise his tenancy. In the webtoon, Sook and Yeong overhear him declaring that the apartment residents deserve to die and kills a resident while locking down the entire building.
