A Spartan of the UNSC falls into Equestria and has various shenanigans in the land. First chapters revolve around how he meets the royalty, the mane six, and the new world in general.

Often called a psychotic, meth dealing hillbilly with a habit of untamed violence and murder sprees, Trevor Philips is someone that no one wants to mess with. The body pile he leaves behind and then sets on fire just for the heck of it proves that. But after a particularly deadly drug deal gone wrong, Trevor finds himself in a place even his disturbed mind has difficulty comprehending.

The feeling is mutual for the ponies.

Rarity meets the stallion of her dreams, a soldier unicorn from Canterlot, but he just isn't into her. Instead, he seems to have an eagle eye out for cute stallions, so Rarity decides to take a few desperate measures.

Written for a fic exchange among the Equestria Daily pre-readers. My prompt was "Rarity meets the stallion of her dreams, but he just isn't into her." Banned from posting on Equestria Daily for entirely justified reasons.

Spartans never die, they're just missing in action. This has never been more true for Jorge-052 as, after activating the slipspace drive that was supposed to kill him, he is instead flung into a strange world where war is but a distant memory. Will the aging soldier be able to adapt to this new peaceful planet? Or will his only salvation be found in finding a way back to his own chaotic universe?

(It's my first time, so be gentle)
Now featuring a TVTropes page by Sabo88

Comet takes his job too seriously. Angel doesn't take anything seriously.

Comet joined to protect kingdom and princess(es). Angel joined for adventure and danger.

Comet isn't interested in mares. Angel can't stop talking about stallions.

Comet is a pegasus. Angel is a bat pony.

Together, this unlikely duo goes through life as Royal Guards from basic training to fully fledged guardsponies. Who knows? Maybe they'll even start to get along.

Cover art by slawomiro.

After GLaDOS is uploaded into a potato battery, Wheatley humiliates the AI even further by uploading her into a project that was abandoned by Aperture a long time ago. In the blink of an eye, she finds herself in a deformed body of flesh and bone that resembles an equine, and is just as powerless as one too. It comes with all of its needs and bodily functions as well. To make matters worse, she's trapped in a land full of insufferable creatures that just want to make 'friends.' Will GLaDOS' cold, sadistic sense of humor and morals get the better of the ponies? Or will they peel away the once artificial being's metallic shell and find that there's a softer side? Probably not, but it's worth a try.

Story Theme: Tyler Bates - I Love You (Watchmen OST)

Thanks to Meeester, MrJoshy, and funkyferret for proofreading/reviewing.

Cover by Fedte16.

Two months have passed since House faked his death to avoid prison and spend time with his best friend, Wilson. Together they have traveled the United States doing whatever it is Wilson wishes to do before he dies from terminal cancer.

The most recent decision was to go to Trentville, a small town with little to offer the pair, apart from an unbeatable drinking challenge.

After successfully completing the challenge House and Wilson pass out in an an alleyway behind the pub, only to wake up in rather different land.

How will House cope in a land that is filled with ideas he believes to be moronic, where kindness and friendship roam free. More importantly, how will Equestria cope with House's cold, hard, cynical logic? Also how will Wilson cope living in a land filled with ideals he has tried to convince House of his whole life?

Not so long ago, Equestria barely defeated two almost unstoppable creatures known as humans, which they called the Second and the First. Almost five years later, another one has shown up. The military takes up arms, the princesses are stricken with fear, and the Elements of Harmony assemble, ready for battle. But 'the Third' has no idea what's going on, and only wants to know how he came to be here, and how to get back home. Good questions indeed...But will he ever get his answers? Or will his predecessors' legacy catch up to him first?

“Side story/prequel to Human by DannyJ, but can be read on its own. Contains spoilers.”

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.