I didn't see any #creepy tag, so I thought I'd try here.
Edit: Thanks for the stories!
Edit: Okay, I'll share one of my own :") Real life story!
I like taking my dog on walks at night, and as I was taking my usual route up the hill, turning right onto another path...I didn't notice anything unusual. It was nice out, indigo sky, nice breeze on a summer night--nice. But when I turned my back, and was walking to go onto another path to continue my walk, I see this "dark figure" a long ways ahead of me. It's in quotation marks because often times, that "dark figure" is a shadow of a light post/tree.
I didn't think anything of it and continued going on, but more cautious of what's happening. My dog wasn't freaking out, or alert, so that relaxed me a bit.
But when i slowed down my pace, it still kept going forwards. When I quicken my steps, it was still moving at the same rate, and I thought, "Oh no...ohnoohnoohno..." I was becoming more freaked out because that thing was swaying, and the arms were moving in an erratic manner around itself. We were the only ones on the entire street. The cars on the busy street were too far away to witness what will happen in this dark end street. Now, it was about ten feet in front of me. It was still swaying, silent, arms moving around itself in a stupor. My heart was racing. I didn't want to look at it in case it jumped out at me, or had eyes that were uncommonly colored (red, white, yellow, etc). I didn't want to have that image ingrained in my brain.
Five feet. Three feet. My dog still isn't freaked out/on alert, and now I'm worried. I can now see them in the poorly lit, orange lighting, "Crap," I thought, "I'm going to be traumatized."
Lo, and behold, it was an elderly lady that lives in my neighborhood doing stretches/exercises. We passed by each other with no trouble, and I finish my walk with my dog. Yup. Just someone stretching their back, and not some broken puppet demon. All went well the rest of the night.
Oh yeah... Friend of mine told me this one on a camping trip earlier this year. It's pretty long but I really enjoyed it. Goes something like this... So this guy is driving from Coeur d'Alene back to his home in Boise. Roughly seven hour drive across Idaho. Lots of nowhere inbetween. He's anxious to see his family again. Thinking about work. Taylor Swift is on the radio. Blank Space. Literally like the thirteenth time he's heard it today. It's become so mind numbing that he almost didn't notice his car breaking down. He stutters to a stop, turns off the radio, and steps outside to survey the damage. It's bad. Engine's smoking. Axle's crooked. Real messed up. He looks both ways down the long and empty road. Just a whole lot of nothing staring back at him. He pulls out his phone to call his wife. Give her the heads up. He's going to be a little late. But unfortunately he cut his Verizon bill in half last month. Switched to Sprint. No cell reception. Damn. Unsure of what to do next, he sits and waits for a car to drive by. Who knows, maybe they can help. And wouldn't you know it – a tow truck pulls up next to him not ten minutes later. And the driver's a mechanic. Owns a repair shop in a town just a mile up the road. Offers the man a lift. The two men pull into the town of Boulder Ridge. Real small town. Gas station, a few houses, Mexican restaurant, an old hotel, and a run down auto body shop. Quaint. In the shop, the car is in bad shape. Axle problems. Never an easy fix. Mechanic figures It'll take at least two days to repair. He directs the man to the little town's one and only hotel. The man arrives at the place. It's pretty shanty. All old and wooden. Creaky floors, dim lighting, outdated furniture, typical creepy fare. A real eye sore. The man approaches the reception counter to ask for a room. "Sorry, we're full!" the receptionist replied with a smirk. A joke, of course. A little way to break the tension. At least she wasn't taking the mood of the place too seriously. She hands the man the key to room 21. Not one of those reprogrammable hotel cards, but an actual brass key. It's heavy, and old, belonging to a bygone era, like the rest of the place. The receptionist leads the man down the hall to his room, but slows to a stop right in front of room 11. She takes a deep breath, turns around, and tells the man to never, ever, under any circumstances, knock on the door to this room. She turned around briskly, before the man could ask her why. Taking her advice for another lighthearted jest, he doesn't worry about it. The two continue to room 21. She shows him the room, then leaves hastily, slamming the door on her way out. The man wondered why her mood had changed so suddenly. The room was just as atrocious as the rest of the place. Old, outdated, and wooden. Bed in the middle of the room. Dilapidated rocking chair in the corner. A few lamps. A TV straight outa 1979. Didn't even turn on. So the man decided to go to bed early. It had been a long day. But he couldn't sleep. The man couldn't stop thinking about he receptionist's odd behavior regarding room 11. It kept him awake for hours on end. Was she serious? She cracked that joke when I asked for a room – the girl was probably just trying to be funny, in a dark way. But she was so nervous. She left the room in a hurry. She slammed the door hard. What could she see that I couldn't? Some time later, the man had had enough. He had to settle this. So he opened his door and walked down the dark hallway to room 11. His palms sweating, his heart beating, his breath racing. He finally built up the courage to investigate. Don't knock on the door... That was the receptionist's instruction. Instead he kneels down to peep through the keyhole. And he saw... An empty room. Exactly the same layout as his. Except for some white cloth draped over the rocking chair in the corner. He shifts his perspective through the keyhole, shimmying on his knees, so as to focus more on that part of the room. It was dark, but his eyes had adjusted. And upon closer inspection, it wasn't just a cloth – it was a person. Deathly pale and wearing all white. Standing out in great contrast with the rest of the shadowy room. The pale figure had turned the chair around so he was facing the corner – thank God, he can't see me. A combination of fear and adrenaline pushed the man to knock on the door – but better judgement held him back. His appetite had been filled. Feeling somewhat satisfied, he made his way back to room 21 and closed his eyes. The next day came. He passed right by room 11 on his way to the lobby without thinking twice about it. The man had quite enough adventure for one night. He thought about talking to the receptionist about what he had seen, but decided against it. The man visited the mechanic to check the progress on his car. One more day. And what an agonizing day it was for the man. Who was that person in room 11? Why was he there? Such thoughts plagued the man all day and well into the night once again. As he lay there sleepless for the second night in a row, he decided to head back to room 11 for a second look. And so he crouched down to look through the keyhole just as he did the night before. But this time what he saw was very different. All he saw was... red. The color red. Not like the room had been painted red – but like a dimensionless, flat red color. He adjusted his perspective like he did the night before, looking this way and that, but it was no use. Something had to be blocking the keyhole. The man eventually came to the conclusion that the pale man had pasted some kind of red card over the keyslot. To prevent strangers from looking in. The pale figure knew.... Before he could blink, the man was back in room 21. He didn't sleep the rest of the night. He lay there in a cold sweat for hours until he watched the sun rise through the thin curtains. It took the man a lot of courage to race down the hallway, past room 11, through the lobby and right up to the reception desk. He demanded he be checked out of this hotel immediately. The receptionist sighed, and slowly took the man's room key and money. "I can tell by the look on your face that you were snooping around room 11 last night, weren't you?" the receptionist asked the man. The man reluctantly agreed. "What the hell was in there?" the man asked. "I guess it's no use keeping it a secret anymore..." the receptionist replied. "We have a resident ghost, an old man, who died in room 11 many years ago. He doesn't do much... Gave me quite a scare when I saw him for the first time a few years back. You know, he's a very peculiar ghost. Not like the typical ones you might see on Halloween. This guy... he's completely white, as a sheet, from head to toe... Except his eyes, which are a bright, scarlet, red." Hope you all enjoyed ;)
My favorite creepypasta (it's pretty famous): The Russian Sleep Experiment.
http://www.angelfire.com/trek/caver/page1.html - Ted the Caver is a classic. So worth the read!