After Tensor's comments on my last post, I decided to divert my series on belief and focus a bit on what exactly Slendyshit is.
The fact is, we don't know. We don't have the slightest fucking clue. Right now it's looking like there are three primary theories, all of which I'm going to cover. There are also a lot of secondary theories that I may cover at some point, but I'm still working two jobs and preparing to fend of Star if needed. So, to business.
Tulpa theory: As stated by M, Robert, Shaun, and a whole mess of others. Primarily associated with the Core Theory these days. In case anyone isn't aware, the idea is that Slenderman didn't exist before Victor Surge's post two years ago on Something Awful. For whatever reason, he grabbed our attention and our belief made him reality. Considering the way information spread about him across the internet, I tend to like this theory.
As far as I can find, outside of firsthand accounts after the fact from bloggers like Tony and proxies like Tensor and incredibly obscure books, no one had ever heard of him until SA. Then references to him started showing up everywhere. Der Ritter, all of the mess at Herakleoplois Magna, all of the references Jean and Thage have found in books.
Even more interestingly, there are no accounts of him from contemporary sources that went up before that SA thread. People like Tensor and Tony only came out and talked about it after. Which could be a simple desire to keep others from being infected, or it could be because they hadn't experienced these things until this thread happened, in a complete mind fuck of timeline insanity. If the concept confuses you, check out Buffy and how Dawn was added to the cast.
Pros: Simple, elegant, believable. The pattern of information makes this seem likely to me, as I mentioned, and it doesn't require belief in other dimensions or supernatural forces.
Cons: Tensor actually raised a good point on that last post. If this is possible, then how, and why did Slendy get Tulpa'd and not some other things that people have believed in just as hard for a lot longer. Or maybe it has? Maybe I should ask Nick about that one.
Conclusion: Overall, this theory is my favorite, because it makes sense. That's how he gets us-he waits till we believe, then strikes. It doesn't feel like a stretch for me to believe that he came into existence the same way.
Reverse Tulpa Theory: As theorized by Maduin and Jay, as well as others. Basically, the idea is that the SA thread brought him to life, but not so much because we believed in him as he used us to get born. A horror stuck firmly in the realm of nightmares, brought by man to the real world to wreak havoc and kill people.
It appeals to a person's sense of the theatrical, and there are certainly plenty of examples, as Maduin points out, of what could have been Slendy trying to intrude on the real world through fiction.
The Tall Man
And so many others. Coincidence? Maybe.
Pros: A good meeting ground between the Tulpa Theory and the Ancient Evil theory. The prevalence of scary tall pale types with tentacles and/or no face does tend to support it.
Cons: Still. An eldrich horror born out of humanity's subconscious fears? Seems a bit like a cheesy horror movie.
Conclusion: I'm not quite convinced. Maybe I'm just not enough of a believer to think that supernatural beings exist in some alternate realm, just waiting to be brought over, but it seems weak to me.
Ancient Evil: This one's getting more and more popular these days. Jay weighed in on it, as did Jean, Zeke, and Ava. In addition, this is the theory Tensor would have me believe, though I don't think that does anything to actually recommend it.
This theory states that all of that nonsense about Egypt and Der Ritter and ancient doings is all true. He really is some ancient evil beyond mortal comprehension, and he really has been around since the dawn of time, without timeline fuckery.
A variant on this theory is that he hibernates for hundreds of years between feeding frenzies or whatever you want to call it when he comes out to eat, and that's why he's only recently popped back up. Slightly different still is the theory that he only exists when enough people believe/are afraid of him, and so he goes away when people forget.
Pros-Smooths out the issues with timeline insanity the other two theories pose, as well as is perhaps the simplest of the three theories
Cons: The main theory doesn't explain why he only has a few recorded periods of heavy activity over the course of human history, and the variants are either blatant ripoffs of Lovecraft (Cthulhu sleeping anyone?) or end up going back to his reliance on belief.
Conclusion: Not buying it. Again, I think I might be just too much of an atheist to buy into the idea of divine or demonic entities.
Now, your mileage may vary. You may believe wholeheartedly in a different theory than me, or you may think that none of it is true. I'm not sure that it matters so much. What matters is fighting back, and until an origin story suggests a weakness, I'm unconvinced as to the relevance of where it came from. We need to understand who/what it is now, so that we can destroy it once and for all.