- "Yes that is it! I am a indisputable genius!"
- — Marlton
His appearance is of a Caucasian male in his twenties. He wears a white-collared shirt, blue jeans, and glasses. His quotes in-game classify him as a stereotypical, "nerd".
Marlton favors using a larger, advanced vocabulary, which either displays his arrogance in the way he views himself, as superior to others, or this is natural to him, as he is very knowledgeable about many contraptions and weapons.
- Main article: TranZit/Quotes#Marlton Johnson
- Main article: Nuketown Zombies/Quotes#Marlton Johnson
- Main article: Die Rise/Quotes#Marlton Johnson
- Marlton has a very high view of himself, as he references the fact that he is an "indisputable genius" in many of his quotes.
- Marlton is self-conscious.
- Marlton is ambidextrous.
- Marlton suffers from claustrophobia, which is the fear of having no escape and being closed in small spaces or rooms.
- He suffers from mysophobia, which is the fear of contamination and germs.
- He refers to the Mystery Box as the chaos box.
- He and Russman have a mutual dislike for each other.
- He is very knowledgeable about weapons, often reeling off facts about the guns he acquires in the Mystery Box.
- Marlton dislikes the Executioner, but strangely, he likes the other shotguns available.
- He is also dismissive of semi-automatic and burst-firing weapons.
- Conversely, he seems to like all weapons that he identifies as of Russian origin, with the exception of the RPG.
- His watch-calculator reads 190438.
- Misty has a crush on Marlton, and he seems to reciprocate those feelings somewhat, despite him saying he feels no emotion and explains that he has a special relationship with Misty.
- Marlton can be heard in Nuketown Zombies, by knifing the bunker in the backyard of the green house.
- His favorite weapon is the DSR 50.