Yoon Gwi-nam

Personality: Gwi-nam, before the outbreak, was a sadistic bully who hurt, exploited, bullied and harassed those around him for fun. He was not the leader, however, and showed respect and even had a friendship with Son Myeong-hwan, the leader of the clique, with some strong hints of insecurity. When the outbreak started, he instantly showed cowardice as he shoved four people into the zombies, one of them being the lunch lady who offered to help. His cowardice is short-lived, however, as he shows competence with killing zombies with very little hurt. His psychopathic tendencies also bloom here as he threatens the principal's life, before tying him up and murdering him in cold blood.

He is careless of others' lives, shoving people into zombies for no reason other than being in the way. When becoming a hybrid, his qualities became worse and he turned more sadistic, egotistical, bloodthirsty and spoiled. His main goal is revenge, wanting to gouge Cheong-san's eye out due to the latter injuring his own eye while he was still human.

His sadism is more outward, as shown such as taunting a dying Jung Min-jae as he turns into a zombie though he doesn't completely eat him due to "respecting" his bravery. He even drops his only redeeming quality as he murders Myeong-hwan and feeds him to zombies. He does show some brief hints of remorse before his final fight with Cheong-san, crying after the latter calls him "nothing more than a monster" but he appears to shed this as he attacks and fights him, even sadistically gouging his eye in vengeance. At his core, Gwi-nam is revealed to be a spoiled brat, getting to a short tantrum when the students didn't recognize him.

He is even more evil in the webcomic, also showing no cowardice around stronger people. He glues the eyes of the teacher and sends her outside to let her become a zombie. Then he steals a bra from a senior female student and uses it as a knee pad. Worse, he sexually assaults a female classmate, and when he sees her menstrual blood, he acts like a zombie and devours her flesh.

Appearance: Gwi-nam is a tall Korean man with short black hair, jeans, and a black shirt with a bloody white uniform underneath. After his first altercation with Cheong-san, he has a large cut on his eye as he wears a zipped-up archer uniform.

In the webtoon, he has a bulky build and an angled jaw.

Biography: Pre-apocalypse; Not much is known about Gwi-nam's early life, except that a year prior to the story, he stole and crashed his father's car. He was a notorious, traitorous, abusive bully at Hyosan High who used to pick on insecure high schoolers to fit in with the other bullies. He and his gang mostly targeted Jin-su, the son of science teacher Lee Byeong-chan. One day, they even went as far as putting him in a washing machine. Mr. Lee wanted the bullies punished for this and bought their behavior to the school board, where Gwi-nam said the were "just joking around". Luckily for them, the principal dismissed their heinous acts as an attempt to maintain the school's image. Later, he and his gang brought Jin-su up to a roof to attack him. Jin-su is displaying odd behavior and tries to bite them, but ultimately the boy falls off the roof. Gwi-nam got one last look at him and cursed.

After this, he moved onto picking on Eun-ji and Cheol-soo, primarily. He bullied them both with his gang until Su-hyeok arrived who told the two victims to leave and grow up. However, Gwi-nam threatened Su-hyeok that he will post the embarrassing pic of Eun-ji right away if he lets Eun-ji and Cheol-soo go, so Su-hyeok let them stay to avoid the risk and continue their shenanigans. Later, in class, Gwi-nam drew on the back of Eun-ji's shirt, causing the whole class to laugh