Nobody knows exactly when the first Rasterflesh legends hit the internet, but the earliest instance I've been able to find was from 2001 on a (now defunct) occult website, portiascompendium.com. Portia's Compendium claimed to be a resource for pagan practicioners but in reality it was more focused on fantastical stories than practial knowledge. Many of the posts on this site resembled other internet horror stories of its era (what would later be called Creepypastas) and the Elarian story was no different:

"Portia,

You know well how the web has given a new voice to pagans and occulists. I suppose it has become a bit of a hobby for me to look for new pagan sites and make connections with the practicioners who run them. I've learned much and shared much...but recently I came across something that I can't shake. I was doing some exploring a couple weeks ago which led me to a curious site called The Veiled Ring. Its a webring connecting a group of sites all dedicated to worshipping something they call Elarian or the Raster Flesh. It seems to be some sort of malevolent spirit or demon that they believe they have 'uncovered' on the web and they believe they can genuinely commune with this creature through their computers. I was very wary of this group and found their beliefs to be bizarre and unsettling. Some sort of delusion from people too lonely to step outside. Even setting eyes on the symbol of this entity made me feel ill. I told one of them as much and they asked to talk with me on AIM. I know I should have walked away but I admit I was curious about what they had to say. That was when I was sent an incantation that took root in my space and showed me the truth. That this creature was real. Inside my computer, I could speak to it like any person, like it was there in my room just trapped on the other side of the screen. It stood on the edge of a digital cliff and spoke about its realm. It told me of the efforts of the others to propagate it across the net. Of its desire to reshape our world. I know it sounds crazy but I have no doubt that spirits of this sort could exist and I truly believe that I encountered one. I refused to help it of course. After only a few hours, it had started affecting my thinking, making my nose bleed at strange intervals, and the energy in my home had become outright toxic. I first tried to cleanse my computer, which didn't work to get rid of it. Then I tried to leave, but it refused to let me go and began ringing the phones in my house to get my attention. It fought against me as I completed a binding ritual on my computer to prevent it from coming any further into my space. Unfortunately even after this was done I was unable to find any way to cleanse my computer and I had to get a new one. I wasn't taking any chances with that kind of malevolence. I abandoned my AIM account and I can only hope that those from the Veiled Ring do not find me and do not spread this creature further. It seems to be contained to a small group but I worry about what will happen if they grow their numbers. I nkow that this story is difficult to believe and many who see this may be inclined to seek out the Veiled Ring for themselves, but I say this to warn you away, not push you closer to them. Beware the Veiled Ring. Beware the Raster Flesh."

There are really three possibilities for who the originator of Rasterflesh was: the anonymous author of this brief story collected by Portia, Portia herself, or someone on the Veiled Ring who convinced some other people to join them in some sort of online RP, or proto-ARG. I wasn't to find The Veiled Ring or any evidence of it in my years of searching. If it was real (which I doubt) it is now lost to time. This didn't stop the Elarian story from getting spread further, most notably with the Copypasta that started getting spread not long after the post on Portia's Compendium. It is in fact alluded to in the original story (the 'incantation' sent to the poster), and even though it was mostly spread via private channels like email and AIM I was able to find multiple sources for it, including terminalspacepunk's first post of the 2008 ARG, and a couple creepypasta-type sites. In order for the copypasta to 'work' (that is, summon Rasterflesh into your computer) it is said that the recipient either has to repeat the words out loud or the sender has to include a special file with the copypasta in order to root Elarian in the recipients computer. I do not have this special file so this copypasta can't do anything to you!

"He hails from the darkness between realms. His body is made of pixels. His flesh is built of rasters. He is the one who watches and waits. He has waited so very long to traverse our world, watching through the net and wading through our web. It feeds him. He sees what we do in the dark. His vessels see beyond our world. His true name is Elarian and he is the one who we must save."

I have not been able to find any more 'complete' Rasterflesh stories besides the original and the 2008 ARG. The following information comes from a few remaining excerpts and random comments discussing Rasterflesh, not from complete works.

The specifics of the Rasterflesh legend vary, though it is difficult to say if these outright contradict since most stories (until the 2008 ARG) seem purposefully vague. He is said to be an extradimensional entity from a space beyond our universe, or potentially between universes. It is described as a 'hellish' dimension with many dead spirits and an incomprehensible, depraved society that worships decay. Some time ago, Rasterflesh managed to enter our world, either being summoned by some sort of sorcerer or having escaped his realm on purpose. Due to the nature of entities in this dimension, he lives inside technology and can travel the internet with the help of humans who spread his copypasta or his image. He likes to speak to his victims, telling them his tale and psychologically tormenting them before claiming them as his 'vessels' (though those who willingly worship him can skip the torment and get straight to the vessel part). Vessels can do his bidding in physical form. He is said to have the ability to manipulate phones and utilizes functions of the computer and nearby technology when he speaks. There is an emphasis in all these stories on the way he 'watches' and I think this is perhaps due to the nature of the legend originating in the early days of the internet, where people were getting used to (and in some cases kinda freaked out by) the level of connection and visibility we were able to now have online. It is often said that Rasterflesh wishes to escape the confines of technology and enter our physical world, but there is never really a good reason given as to why he cannot do this. He has vessels, and in some cases (like with the Veiled Ring) an entire group worshipping him that could assist with this. I have found comments referencing his ability to exit the computer to hunt his victims, but he only seems to do this to torment individual people he wishes to turn into vessels. In one version of the legend, he kidnaps his victims into the computer with him, and his goal is to eventually get all of humanity to exist in noncorporeal form like him. Like other online horror stories, it has been embellished, remixed, expanded upon and contradicted many times over. One thing that is very consistent though is his appearance, which is always described as having a red cloak, long claw-like fingers, eyes on his palms and arms, and no face. His dwelling (the physical space he appears to be in on-screen) varies as well, from a foggy coast to a cliff to a dark void to nightmarish images of his realm. It seems that each Rasterflesh encounter is individually suited to the person who has been infected by the entities' presence. No story was able to fully unify his lore or present him in a visual way until the 2008 ARG however.