Humans.

Truth or myth? Ancient lost civilization or just an old pony's tale?

No pony has ever seen one, and most haven't even heard of them. But Lyra knows that these wonderful creatures are more than just old legends, and she's going to find out... and possibly drive her roommate insane in the process.

During a traumatic event, an outsider finds himself flung violently into Equestria. His physical form is warped into that of the inhabitants but will his mentality follow? And even more importantly, will anypony truly accept him for who he is? Take a journey alongside this inexperienced youth as he finds himself in a strange new world with very different customs and tries his hardest to find a place for himself where he didn't before. A pity he can't even remember his name...

Okay, the basics. It's first person almost entirely. Very, very long chapters. I try to wrap them up around twelve to thirteen pages but a few slipped over that, especially towards the end. I'll release them slightly stagnated, as I'll be making final revisions as I go. Character tags are NOT final. I'll add more main characters as they show up in each chapter. Expect an update one or two times a week, probably. I adore reviews and structured, constructive criticism. Even if you just want to say you like it, that's fine too. :) I write stories to entertain peoples, so any evidence I get that it's working will encourage me. I hope you enjoy the story!

Applejack finds a strange visitor in her apple orchard one day, with even stranger stories to tell...
MLP/L4D2 crossover. My first story on FiMfiction.net! May add more tags as story progresses.
Credit for the image goes to brokencreation on DeviantArt.

A person wakes up in a forest with no memories at all, now when you combine this with the gear he woke up in he's very suspicious of who he is...

Twilight Sparkle believes she has perfected a process to allow Earth Ponies and Pegasi to teleport. Unfortunately, in the Land of Ooo, a bubblgum-haired princess is about to run a similar experiment. Will even all of the friendship in Equestria be enough to settle Finn down? Will Pinkie Pie ever get her doughnut? Perhaps along the way, everyone will learn that truly, friendship is ALGEBRAIC!

There is a sequel, and a threequel to this...

For the longest time, peace settled in New York City. Young Peter Parker, otherwise known as the Amazing Spider-Man, got a long, relaxing break. No goblins, no rhinos, no lizards. But this will all change, as it always does for Spider-Man. He must save the day again, but this time, things have changed. Dr. Octopus has created a universal traveling vortex, that can teleport any being to a new dimension. Spider-Man must seek the help of Madam Web to grab hold of the new land he has fallen to: Equestria.
Adventure, and Action will pursue.

A long forgotten and believed dead enemy, now more powerful than ever, is returning to Earth. Lead by the circumstances, its protector sends him to a distant land. Weak and with an unfamiliar body, the proud warrior will search for a way to retrieve his old life back, but not without meeting some unique characters on the way.

Part 1: Lyra's Pyro Predicament
Part 2: Twilight's Demoman Devastation
Part 3: King Sombra's Robotic Retaliation

When a mishap causes two para-dimensional weapons to colide with one another, RED Team's Pyro is sent flying from the Team Fortress 2 universe into the alternate universe of My Little Pony, where he is almost instantly discovered by Lyra, who shelters him in her home.

Having him hidden in her small townhouse isn't easy; keeping him from setting things on fire, teaching him that not every cart that passes by is cause for alarm, and that blue ponies are not something to be suspicious of.

However, with Nightmare Night soon approaching, Princess Luna feels that there may be something more sinister riding on the coat tails of Pyro's grand entrance; the first human to ever set foot in Equestria some thousand years ago...

...My name is Alex Mercer. I'm the reason for all of this. They call me a killer, a monster, a terrorist... I'm all of these things. Three weeks ago someone released a lethal virus in Penn Station. I woke up at the morgue. Now I hunt, I kill, I consume, I become. I'm gonna find out who did this to me... And I'm gonna make them pay.

A minor accident at Sweet Apple Acres sends Big Macintosh to Ponyville in the middle of applebuck season. At first, things seem fine. But then some of the mares begin acting a little...oddly.

Then very oddly. Turns out every other stallion skipped town for a very good reason.