Slendy, all he ever wanted was a good home, nice friends, maybe some food. He never wanted to hurt anypony, he’d just wanted to talk to them, and to help them out of the Everfree forest if they lost their way, but whenever they saw him, they would always turn and run.
The only friend he’s ever had was a pet timber wolf named Fluffy. Although Fluffy was a very stereotypical dog name, Slendy felt the name fit the large, overpowered Timber Wolf. He didn't know why; it just felt… right.
Slendy was stalking around the forest, near the border of the Old Castle when he sensed a disturbance. The Old Castle was the original place of rule for Celestia, Luna, and even Discord.
Looking around, Slendy quickly moved into the nearest shadow, which happened to be under the castle wall. Letting himself fall into the shadows, Slendy traveled to the highest shadow; the shadow of the north wall at the top of the Lost Tower. This tower wasn't really lost, just very high up, not to mention old, and dangerous to get to. When he got there, he saw a sight that he had not seen in a very long time.
The two royal sisters and Discord were flying towards the Castle. The last time he had seen the trio together, they had been locked in mortal combat against one another. This night, however, there were no screams of anguish or bright flashes of light as magic flew, destroying the shadows in which Slendy resides; this time, there was only the quite sound of wings.
As the trio approached, their voices pierced the shroud of the night and the peace of the shadows.
Slendy hear Luna speak first. "He's not going to be here! Even if he is, how would we convince him to come out?"
"Not only that, sister, he is more powerful, not to mention much more ancient all of us- Yes, even you, Discord." Celestia said, giving Discord a look of mild annoyance.
"Now, yes, but—" Discord began.
"No buts, Discord. I'm still not quite sure why you dragged us all the way out here. This place- it gives me the shivers." Celestia shuddered, completely unaware of the creature listening in from the shadows.
Slendy remembered the way the three had used to bicker like this, before the craziness happened. They had all just been fillies.
"Discord, no magic! That isn't fair!" Celestia laughed as she flew from Discord, who vainly attempted to catch her.
"Well, you're using your wings!" he countered.
"But I'M a MARE! We mustn’t get dirty!" Celestia mimicked the voice of an older mare that was currently asleep under a tree. None of the beings noticed Slendy watching from the shadows of a massive tree.
"Cece, can you come and pwa wif me?" Luna whined, tired of waiting on the ground next to the old mare, who was supposed to be a guardian and teacher to the two royal sisters. She served more as a nanny, or grandma, then someone who could actually lay down rules of any sort.
"Lulu, come on. Let mean ol' Celestia fly around and I'LL show you how to fly like a real Drag- Alicorn." The young Luna laughed and put out her arms.
Discord swopped down to pick her up, but Celestia was there first. "No way, Discord! My sister, my teachings!"
Discord smirked. "Oh really? Well, how can you teach her when you're in underwater?" Celestia suddenly found herself underneath the surface of a nearby pond.
She struggled to the top, she yelled at the top of her lungs, "Discord! Now you're in for it!"
The memory faded as the now adult trio flew by the tower for the second time. "Discord, can you explain NOW why you brought us both out here on a chase for a ancient myth when I should be dream-walking?" Luna complained.
"Well, I was going through your big library and found a book of ancient Myths. I mean myths older than equestrian, even older than us." Discord explained.
"Yes? And?" Celestia questioned.
"And, if you'll let me get to it," Discord clearly enjoyed the feeling of power over the two frustrated mares, "I found a myth. It was about a being that was called Slender Man. This being walked through the shadows, watching and stalking all those that dared enter his reign. The myth didn't elaborate, just said that he was created ‘in the time when the Sapiens created him.’ I have no idea what that means."
Slendy blocked out everything else and thought.
Yes, he could remember a very long time ago, when there were no ponies but horses, ones that couldn't talk. He remembered running- no, being carried by somepony, or someone rather. They were running. There were cracks of gunfire overhead, and yells to Stop. Whoever was holding him didn't.
Slendy remembered looking around and briefly seeing several other shapes running into the darkness. Then everything just went black. Suddenly he was at peace.
Pulling himself back into the present, Slendy remembered all those millennia ago when a human had carried him out of a laboratory along with several other ‘specimens’; the origin of ponykind. Those had repopulated, and the humans had killed themselves by that time through other means. He couldn't remember what, but it didn't really matter.
Despite remembering this Slendy couldn't remember where the Alicorns and Discord had come from…maybe last ditch efforts to re-start the program that had created him and the first of the other ponies? It didn't matter.
And for the first time in almost 10,000 years, Slendy stepped out from the shadows.
The reaction from the trio was immediate. "Who goes there?" Luna shouted, as she suddenly became aware of a presence that had recently been hidden.
"Come out or we will—" Celestia said, before being cut off by Discord.
"What Celestia? What would we do?"
"Shut up, both of you. I feel something." Luna said, breaking them up, although she couldn’t help but notice the look Celestia shot at Discord just as she started to look towards this creature.
Slendy spoke for the first time in 10,000 years. "I am here."
The only thought as the trio rounded on him, gaping, was what he was going to do with Fluffy.