The Mold is currently a mystery, with no definate origin yet revealed. We don't even know what it's called. Some have expressed frustration trying to understand it, while others have gone so far as to dismiss the idea of trying to take it seriously. I've heard similiar statements made towards the C-Virus, yet like C, so much of how it operates can be seen simply by studying subtle (and obvious) tendencies in mutant hosts. I decided to place this in the 2018+ section, as even though it currently relies on information from RE7, we will no doubt see the Mold again, and this can be a place to compile future information and discuss it. For now, I will attempt to explain how I percieve the Mold, relying both on established fact and plausable speculation.
What is The Mold?
The Mold is a fungus (the term bacteria is used, but this is a mistranslation). It resembles typical mold, and is black in color. While it gives off the illusion of possesing intelligence, the Mold is simply controlled by a "Subject", and is no more capable of thought than my fingers can think independantly of me. It is capable of growing at an alarming rate, and without a Subject to control it's growth, poses an extremely high biohazard risk. It is parasitic, and invades biological organisms to feed on hosts at the cellular level. It is highly toxic, and it's presence is often marked by the corpses of birds and fish.
The Mold is able to grow across an enviroment and invade animals directly, but is also able to infect animals directly from other hosts via skin contact. As a fungus, it can travel in spores that can be inhaled. It can also quickly spread through ingestion, either directly or through contaminated foods. These factors make the Mold one of the most virulent plagues in the series, which is really saying something.
The Mold produces chemicals related to telemores that have extremely powerful regenerative capabilities. These can cause animal cells to divide and heal so rapidly that wounds will disappear in mere seconds. These also may effect how host cells age, and can even cause the restotration of already dead cells.
In it's natural, the Mold does not seem to actually invade and mutate cells like a virus would. Rather, it literally devours animals from the inside out. The resulting Mold takes on the shape of the host it is "eating", and repurposes organic tissue to form muscle and bone that allow the colony of Mold to walk, move it's arms and bite. Like Mimicry Marcus, these colonies, or "Molded", are not infected animals, but merely mimic them. Molded based on humans are so far the only encountered. The Mold is also capable of creating Molded from it's own biomass, so their numbers are indefinate.
Infection and Symbiosis
While the Mold naturally acts more like a parasite and predator than a disease, by controlling how it spreads using a Subject, it can infect host cells rather than devour them.
After invading the body, it can then enter a sort of dormancy, using it's energy not to grow, but to release it's regenerative chemicals and manipulate the host, forming a symbiotic relationship where the host is protected and the Mold can feed on what the host ingests. This seems to cause hosts to engage in strictly carnivouras acts, including cannibalism.
Upon reaching the brain, the Mold develops fungal tumors which gradually damage the forebrain, reducing inhibitions and causing hallucinations. The Mold itself induces psychosis and makes hosts become delusional, prone to rage, and filled with violent, even sadistic tendencies. These result in actions of violence against non infected, infected, and even towards themselves. These hallucinations are triggered and controlled by the Subject, but more on that later.
While the Mold degrades the ego and damages the host's perception of reality, it does not eliminate individual personality, nor does it technically use mind control, at least not in the same sense as Las Plagas. Rather, it breaks down inhibitions, creates an obsession with pleasing the Subject, and puts the host in a state where they are vulnerable to suggestion, like hypnosis.
For example, Jack Baker's fatherly nature and desire to protect and preserve his family remained after infection, but it was perverted to protect Eveline's "family". Marguerite's motherly instincts were used to cause her to feed captured people infected food, and she treated her insects like children. When Eveline ordered Mia to kill Ethan, she rationalized it as a nessesary measure to contain the outbreak.
As the Mold manipulates the biological makeup of hosts, it causes visual, yet superficial mutations. Large bumps appear on the head, likely the Mold tumors, deforming host faces. The skin becomes pale, and black spots sometimes appear as the Mold infects the skin.
The regenerative augmentation the Mold provides also affects host strength, allowing amazing feats like tearing apart cars and walking through walls.
Just look at Jack and Marguerite's appearance before and after infection yourselves:
If the Subject allows the Mold to operate without proper direction (the entire infection process is completely dependant on Subject intervention), host mutations escalate until the host's form is compromised, and they are twisted and mutated into monsters. This stage is triggered by increased Mold activity due to a response to host damage, like V-ACT. This was seen with Jack at the boathouse, Marguerite at the greenhouse, and Lucas at the labs.
The Mold is also said to mutate infected plants•, and mutant Alligators have also been encountered. I will talk about insects later.
A Subject is a human host fused with the Mold at the embryonic stage, like Eveline. Subjects develop a unique relationship with the Mold, and are able to secrete a variant of the fungus that they are biologically linked to. The Subject uses chemicals similar to pheremones, the nature of which are poorly understood even by the Connections, to establish control over the Mold they produce.
The Subject and the Mold collective act as a single organism. In a sense, the Mold is a part of the Subject. When no Subject is present, the Mold is an uncontrollable plague that spreads and consumes everything in it's path. When a Subject is present, the Mold is an intelligent super organism that is only as dangerous as the Subject wills it to be. If the Subject itself is perfected, the Mold would be the perfect bioweapon.
Molded, while posessing little to no intelligence, can behave in a coordinated and cooperative manner when a Subject is present. As stated before, Subjects can also create "Mold Humans", which become obsessed with pleasing the Subject. Even the Mold itself grows and receeds according to the will of the Subject, to such a degree that it becomes capable of autonomy, like The Blob.
Even deeper, the Subject seems to maintain a sort of hive mind between hosts. Mold Mutants' minds may be literally "stored" in the actual Mold, explaining how hosts like Jack could retain memories despite having his brain destroyed on multiple occasions.
The Subjects themeselves are highly unstable, and prone to insanity without regular treatments. These treatments also slow ageing, as Subjects otherwise mature then decay rapidly. Eveline wasn't old enough to start school when she was already a frail old woman.
Control is also an issue, and relies on traditional conditioning.
The Mold has a curious relationship with arthropods, particularly insects, arachnids, and centipedes. In the cases of Marguerite and "Swamp Man" Jack, insects were drawn to and/or produced by them. Marguerite's Mold was used as hives, and her own body housed many creatures that frequently travelled outside through her mouth. The fact spiders were often used to cover doors and flying insects to guard choke points suggests they too are a part of the hive mind, explaining Marguerite's affection for them as a part of her family.
(EDIT: According to the Kaitia Shinso Guide, Insects in RE7 are not controlled by Eveline due to being secondary infected. This resulted in their separation from the hive mind.)
A mutation seen in flying insects is a dramatic size increase, and genetic recombination resulting in insect chimeras, like Plague Crawlers. Sound familiar?*
* The Mold's regenerative and mutagenic prowess and the ability of a single Subject to control lesser hosts, combined with it's effects on plants and insects, makes me believe a connection to t-Veronica is highly plausable, especially with the technical assistance from HCF in 2000. This would mantain Progenitor as the series constant, and a virus/mold connection has already been hinted at.
That's enough for one post. I plan on also covering the different variants of Mold, as well as the different types of Molded. In the meantime, do you agree or disagree with anything I wrote? Have any Mold related questions, thoughts or theories? What opinions do you have? Personally, I really like the Mold, and find the concept incredibly interesting and disturbing.