I am inside your home.
Intruder Alert
The flicker of the TV illuminated this bedroom, drowning out the darkness with his favorite programs. Do you remember how we became friends? The light scared off all the monsters. It kept him safe. Do you remember my face? With contorted flesh, and broken bones, I made myself known. Do you remember my touch? I cradled him in my arms. My sweet boy. I took him away. Do you remember that night, Murray? When you stare into the mirror, you see the same monsters from your bedroom, don't you? But your skin is not your own. YOU'RE NOT THE REAL YOU.
6 revealing the truth about Adam.
6[2], known colliqually as the Intruder, is the secondary antagonist of The Mandela Catalogue, a mysterious force which caused the disappearance of 3,426 children throughout several counties, resulting in the ban of most screen-based technologies and mirrors by 2009.
Appearance
6 seems to take on two forms.
The first being a tall, pale faced man wearing a black hoodie or robe. Mark originally depicts him with a large smile.
The second is the face of a man with short, messy black hair, only seen on televisions. Occasionally his expression changes to an eerie smile. This is the form we see most often.
Biography
The Mandela Catalogue Vol. 1
6 makes its first appearance near the end of the episode when, during a showing of Mark Heathcliff's "scary night", Mark wrote about his encounter with 6 with a drawn reference.
6 makes another appearance during Section Two of the Toddler Stress Assessment when their face appears on-screen with text reading "an intruder".
Intruder Alert

With a new design, 6 makes his first prominent appearance by being the eponymous antagonist of Intruder Alert, being the first thing we see on screen, saying "I am inside your home".
During an educational film hosted by the Mandela County Child Endangerment Awareness Association, 6 is seen throughout. This eventually leads to them kidnapping a child from their crib, causing the mother of the child to hang herself in grief, all of this while Ave Maria plays. It is revealed that 6 has kidnapped 3,426 children within the surrounding area.
Whilst the home of the mother is under investigation by Mandela County Police, security footage occasionally shows 6 in the house, even toying with the mother's corpse as a mockery to the Police Department and anyone who is trying to investigate him in general. 6 is not labeled as an Alternate, raising the question if he even is one.
Exhibition
6 makes a quick cameo in Exhibition when, while Mark is recording an analogue television, a silhouetted face slowly emerges from the screen as Ave Maria plays once more.
The Mandela Catalogue Vol. 2
6 first appears after Adam falls asleep, where 6 speaks to him. 6 calls Adam a fool for "following the shepherds", telling Adam to follow his voice instead, threatening to "wake the others". A frame of 6 in his hooded attire is shown, where he says "Open your eyes".
6 later appears in the basement of the Torres family home inside an analogue television. When asked by Adam what he is, he asks "you don't remember me?" implying a former connection between the two. 6 taunts Adam by showing him subliminal imagery and telling him that no one will save him.
The Mandela Catalogue Vol. 333
6 appears in the form of Stanley, the main character in a short titled The Might of the Subconscious where he tricks children into summoning alternates into their home.
6 then makes a brief appearance near the end when Thatcher Davis and Ruth Weaver investigate the Murray household.
The Mandela Catalogue Vol. 4
6 messages Adam as a spam call, making their appearance known to Adam when he attempts to respond back. 6 asks Adam if he remembers him, reminiscing about when he kidnapped Adam as a child. 6 tells Adam he isn't himself before being cut off by a voice message from Sarah Heathcliff.
Presto
6 has an appearance with a man after Adam says that God told him that Jonah is his fault.
Trivia
- 6 has the most appearances of any character in the series, appearing in eight videos thus far, with Thatcher Davis as a close second with six total appearances.
- The original image used for 6 comes from a real police sketch, that later became a meme.
- According to Alex in a tweet, he found the original photo of the intruder on an online site that belonged to a sketch drawing of a criminal.
- 6's appearance at the end of Vol. 1 revived the meme, where people would repost the image as a form of dark humor, subsequently boosting The Mandela Catalogue's popularity.
- Alex Kister used the image of 6 after seeing it on the thumbnail of YouTuber Wendigoon's conspriacy theory iceberg.
- Wendigoon himself pointed this out as coming full circle, as he is a large fan of the series and is scared of the appearance of 6, saying he caused this to himself.