Thirty two year old Wook Pyeon, also called Mr. Mobster by some of the other residents, is a former police detective and a resident of Green Roof Apartments. He is fierce-looking and he appears to have a gangster manner. However, he calls himself a "good fella". He got fired for putting the son of an important person in hospital. Due to his background, he is more aggressive than others. He still uses physical force to keep others in line, such as Hyun Cha. Despite this, he means well and will selflessly put his life on the line to save others. He appears confident in his ability to live and does not see his acts as a sacrifice, believing he will be able to come back alive. This confidence is borderline reckless: initially, he preferred to fight monsters barehanded, despite their superior strength and unpredictable abilities. He has a strong sense of justice and keeps count of the monsters he killed.