Many thousands of years ago during the rule of the twin sisters, there was no Canterlot. There was a mountain Swiss cheesed by mines. The mines were filled with a great many valuable gems and crystals, as the mountain was a strange geological place. It was strange from the sheer amount of precious gems and crystals that were found, and they found literally everything known to ponykind. Diamonds, rubies, topaz, amethysts, the list goes on. They found enough gems to lower the price of jewelry for over hundreds of years, and it would've gotten better... If it wasn't for the worst discovery known to the Princesses...

One day, a miner decided to dig away at the deepest shaft in the mine. He was a red unicorn in a plaid flannel and a pair of jeans who brought down a pickaxe and a shovel. He picked and shoveled at the shaft, making it ever so deeper as he worked away the hours, until he hit a stone that would not break by his pickaxe. He picked the stone around it, and found that it was covered by symbols in an unfamiliar tongue. He touched the stone with his hand, and it revealed to be a door to a room filled with strange eggs that seemed to connected to an almost artistic cocoon-like substance that coated the surface. He light up his horn, walked into the room, and was never seen again.

Due to his disappearance, a squad of Royal Guards was sent to investigate the way he went down. They disappeared along with him, so a Royal Guard camp was made in front of the shaft where the ponies disappeared to make sure that no pony entered and to capture whatever caused the disappearances. Celestia had communication with the camp through magic crystal mirrors that showed what was happening through the sister mirror, and she watched in horror as she saw exactly what caused the disappearances. It was a black creature that was around the same size as the the guards it sliced it's way through. It had sharp claws on it's hands and hooves along with black blades in it's arms. It also had a small mouth within it's mouth, which Celestia found out about as the small second mouth punched straight through a guard's head. Through the helm and everything. Celestia roughly recognized it as a Tarkatan, a race of humanoids from Shao Kahn's Outworld that have retractable bone blades in their arms. But this creature isn't even a full Tarkatan, it just has similar teeth and blades in it's arms. Then it hit her when another of the black creatures ran up. This one had more normal teeth and a Unicorn's horn on it's head. These creatures must've been some kind of as far as she was concerned, and she wanted to find a cure.

She had many of her best guards and unicorns go down the shaft to capture these poor infected ponies and the Tarkatan, only to lose every one to the infected. After every loss, she had herself and her sister go down into the shaft of many disappearances and deaths. When the Sisters of Equestria made it to the shaft, they were horrified by what they saw. They saw the black cocooned walls of the shaft and found the bodies of every pony that disappeared. It was then that they found out that this was no infection. It was an infestation. Luna was ambushed by the Tarkatan-like creature, but she captured it in a field of powerful magic. Not the levitation kind, but a magic that encased the creature in a magic stasis crystal. The sisters went back to their castle where Celestia and a group of the smartest scientists in all Equestria studied the life from. They deemed it a xenomorphic life form, and ended up giving it the identification of Xenomorph as all known evidence pointed towards the creatures giving victims parasites and these parasites grew into becoming these Xenomorphs. They also thought that the parasites gained some physical and visual traits from their host when they grew full size, such as the sighted Unicorn Xenomorph or their captured Tarkatan Xenomorph... But the Tarkatan born Xenomorph had escaped when Luna lost concentration. It ripped and tore its way through through castle guards until Luna captured it again, and this time it was encased in a spellbound crystal.

After the gathered research, the sisters determined that these creatures are too dangerous to be allowed rights. Due to this, they banned mining in Canterlot Mountain, due to an outbreak of the Demons of Canterlot Mines. Demons encased in a spellbound crystal that was locked by the the words "Shall no one for any reason release these horrid creatures. Shall they remain in an eternal slumber and never waken, for they are too dangerous to kill.

That was enough years ago for Celestia to build a castle on top of the mines when Luna was corrupted by Nightmare Moon and destroyed the old castle. Celestia worried about the spell. She worried that it would break one day. She also worried specifically about the Tarkatan born Xenomorph, because it seemed to hold intelligence in the way it almost skillfully killed everything that it did. And Luna cast the spell that trapped the Xenomorphs in their crystal prison, Celestia didn't want to risk waking the Demons. So the Tarkatan born Demon remaind hidden within the very stone walls of the new castle at the new Canterlot, with a powerful magic to hide the Demon more. After a while, it became known as the Demon of Canterlot Castle. And it remained hidden...

But no one can truly predict the random happenings that the future holds.

A thousand years later, when Celestia found the Elements of Harmony, when she got her sister back, when The Changelings attacked, when The Crystal Empire returned... She would have never predicted that the clans of the Viking Caribou would collect into one empire under one name... And that name was Dainn, the king of the Caribou Empire.

After the quiet town of Lindisbarne was stormed, after the several towns after were taken over, after Canterlot was invaded, after an entire gender was forced into slavery... Celestia knew what she had to do. She was easily captured, but only because she was found trying to do something that almost backfired. She tried to hide the Demon of Canterlot Castle...

Celestia is flying away from the sound of armored warriors that are after her. They want her for her body, but they don't know the importantance of what she's trying to do. She's trying to find where she had the Tarkatan born creature hidden so she can have its prison's magic presence hidden from the Caribou. She doesn't even know what they would do with the things, as they truly can't be tamed. They would likely try to enslave them and release the beasts to wipe out everything. Where she needs to be isn't too far away, but what matters is how much she will be able to concentrate.

"This should be the room." Celestia tells herself, too tired to think to herself, "Now concentrate, 'Tia. The lives of many depend on this."

Celestia's horn glows inside a room, and the light reveals an empty closet. It was left empty ever since construction out of the claim that hissing could be heard from time to time. As Celestia felt exactly what she was looking for, she heard the warriors behind her. Three of them, all strong, large, and hungry Caribou looking right at what they were told to bring to Dainn.... And he said they get to try her first. Behind the Caribou, a War Beast follows closely behind as a secondary means to stop Celestia. If she kills the warriors, the War Beast would attempt to overwhelm her. You never know, she is an Alicorn.

"So, Celestia." One of the Caribou says in a dark tone that's filled with a thirst, "What are we trying to do right now? Create a trap?"

"Please, let me seal it for good!" Celestia pleads, trying to gain the concentration to seal the Tarkatan hybrid with a stronger spell.

"Seal what for good?" A second Caribou ask, this one with a higher pitch and a more joyous voice. "Your mouth? I can use my cock for that!"

"I need to seal the Xenomorph in the walls of this castle, or we will all fall!" Celestia warns the warriors. The last Caribou doesn't say a thing until he feels Celestia's legs and kicks her to the ground, causing sparks to fly from Celestia's horn. As the sparks fly, a sharp screech goes off, but is unheard by the warriors.

"I don't know about those two," the third Caribou says, this one with a more leading and psychotic tone "but I don't care what you're trying to do. You're going to be our king's bitch! If it was up to me, I would break horn and rip your wings off. But I have orders against doing so, Dainn doesn't want to take your horn and wings like he's done with ever other mare in your precious Equestria. He's going to fuck you until you break and surrender to him. You cannot stop this, slut."

"PLEASE!!! I Don't Care What You Bastards Do To Me, I Need To Save Us All From A Horrible Creature That Will Kill Us All!" Celestia yells out in great anger.

"What even is a 'Xenomorph'?" The third Caribou asks.

"Long ago before this castle stood, this mountain was used for mining precious gemstones and crystals." Celestia says, trying to be as clear as possible, "It's still filled with enough crystal and gems to make anyone richer than anything on this world. But all mining stopped because of a discovery that's responsible for the deaths of many. We discovered these creatures that use others to grow and incubate their young. And they gain physical traits of their hosts. Have you ever heard of Tarkatans?"

"In children's stories, yes." The third Caribou says, "Creatures from another world that supposedly have blades in-" The wall behind Celestia begins to melt, "Oh, I see. You district us from our job so you can melt the room, is that it?" The leader removes the armor that protects his groin, and tosses it aside. It reveals his erecting member as he smirks, "I will have your innocence, slut. Nothing can-"

*ssssssssssssssss*

"What was that?" The first Caribou asks.

*hhhhhhhhhhi-huuuuuuuuuu*

"I have failed. I have failed you all..." Celestia utters before a tail with a spiked tip points down at Celestia's back

*RESESESESESESESESESESE*

Celestia is impaled by the tail, is flung into a newly melted hole in the wall, and a black creature is revealed... The Tarkatan Xenomorph. It stands tall, reaching eight feet in hight. It's head is a somewhat long dome that reflects the faces of the soon-to-be victims. Ittbody is bulky, covered in muscle and ribbed surfaces of many different kinds. And on it's arms are the tips of what appear to be black spears of some kind. It's almost artistic appeal towers over the Caribou that have no clue what horrors this creature is capable of.

"Boss, I have a bad feeling about this thing. " The higher pitched Caribou says. The creature growls as it stares at the fur covered warriors.

"Oh, spare me the dramatic entrance, beast!" The leader says, sounding too confident about himself. He draws out a sword and points it at the abomination, "I have fought against many, and you will just become another forgotten face." He swings is sword into position, and charges for the alien, "Die!" The creature screeches as the leader swings his sword at the creature, only for one of the spearheads to extend into a full sized blade and block the swing. It's second spearhead extends into a blade as well, and impales the leader of the three Caribou, "GAH!!!... What-uh black sorcery conjured you?" The Xenomorph lets set another screech as it slices the Caribou's head off, and the others watch in horror as their leader has just been killed.

The War Beast catches the excitement, and charges into the doorway, only for its massive body to become stuck in the stone that the entire castle is made from. The Xeno looks over to the beast and leaps into its head, stabbing its blades deep into the beast's scalp. The beast cries out as it's resilience has allowed it to survive and suffer while the black monster opens its jagged tooth covered jaws and unleashes a hidden inner mouth that punches into the War Beast's head. The smaller mouth pulls out, bringing some brains with it as the Xenomorph stabs the War Beast one last time using the tip of it's tail to deliver the final blow. The War Beast falls and the Xeno jumps for the ceiling as the two remaining Caribou draw their swords.

"You Killed Gerald!" The two remaining victims cried out in anger, both charging the Xeno at once. It proves to be a mistake as the two swing their swords, and the black creature ducks and wraps its tail around the higher pitched Caribou's legs. The Xeno pulls back, rips the legs of the Caribou, impales the warrior in the chest with its tail, then throws him into the remaining Caribou. The legless torso knocks the remaining Caribou off his hooves; and the Xeno pounces onto him, staring into the final victim's eyes.

"By the gods above! W-what do you want with me!?" The Xenomorph grabs the Caribou by the back of his head, and brings it closer to its face, "No! Don't Do It! I'm A Virgin!" The black creature connects its mouth to the final Caribou's mouth in a parody of a kiss. What it's really doing is implanting an embryo into the Caribou, in order to expand its numbers.

Celestia stumbles out of the melted hole in the wall, and watches the impregnation in complete horror. She has a hole in her chest from being impaled and thrown, but Alicorns are tougher than their soft skin would suggest. The Xeno finishes implanting the embryo, and bashes the Caribou unconscious.

"Mother of me..." Celestia says, feeling sorry for the fighters who have witnessed the ferocity of the creature. The Tarkatan hybrid looks back at Celestia, then at the dead War Beast that's blocking the way out. The creature spits acid at the top of the doorway, giving it a hole small enough for it to escape. It crawls through the hole, and disappears as more Caribou are heard in the distance along with the sound of a struggling male voice.

"Get Your Stinking Paws Off Me, You Damn Dirty Caribou!" The struggling male yells out.

"What? I'm just checking what's taking those men of mine so long..." Celestia recognizes those voices. The struggling one is one of her most trusted guards, Nickelmane. The other voice is Dainn, king of the Caribou Empire, "What by the gods-What is that War Beast doing in the doorway? Move it out of the way!" Hoofsteps are heard moving close to the War Beast, and the massive beast is pulled out of the doorway. Celestia is seen injured and afraid. But Dainn thinks differently, "So, you've made quite a mess, Celestia. I'm still thinking of a new name to give you, Celestia doesn't fit after what you have done."

"I didn't do this!" Celestia cried out, "The De-"

"Ah, yes! The Hideous Demon of Canterlot Castle!" Dainn said in a jolly attitude, "A child's story meant to scare young fillies and colts into not breaking into the castle they live near! Ha-I see why some nickname you Trollestia. You take joy in spooking others due to how boring your position is."

"Please, it left the room not too long ago!" Celestia warned, "And it impaled my chest! Please Believe Me!"

"A pity, really." Dainn said, thinking about why Celestia would kill, "Your killing of some of my greatest warriors -and the death of their pet- isn't going unpunished... I guess I'll have to take your horn and wings because of it."

"I AM NOT A KILLER!!!" Celestia yells out in great anger.

One of the Caribou accompanying Dainn walks over to the surviving deadman.

"My lord!" The follower says.

"What is it?" Dainn responds.

"They're not all dead, sir. This one is still breathing."

"He survived Celestia's attack?" Dain says in an acted form of surprise, "Maybe the whore still had an ounce of mercy left! Give him a room and a bitch. He deserves it."

"Yes sir." The follower says, fetching some other followers to help him.

"And someone put the whore in a cage," Dain demands, "I want her to be kept near my throne in case I want a mouth on my cock." With that, a Caribou with a chain wraps the chain around Celestia's neck and yanks her away. Celestia follows, but with an angry look upon her face. Dain walks into the room to get a better look at what he thinks Celestia did. "My, what a display. It's a good thing I'm having her horn removed, or else she might've killed me in my sleep. I mean, she can melt stone with some kind of faux-acid attack! And she cleanly severed a head! And repeatedly stabbed the War Beast! These are no easy feats... Though I will admit, it does roughly look like what those children's stories described. Only this shows something that can intelligently fight. Celestia must have some unknown skills in swordsmanship. I must show caution and break her mind. What do you think, Nickelmane?"

"Celestia isn't lying, you know." Nickelmane says, now smiling, "I wasn't alive when her sister sealed it, but it was kept in a spellbound crystal that even Luna wasn't sure would hold due to its acid blood. Just look at the doorway." Dainn looks over to the doorway, spotting the melted stone and blood covered prints. Dain rushes out into the hallway, and sees the prints go into a rather large AC shaft, "It's probably going to pick off the staff of this place as they come."

"An intriguing thought..." Dain says, not believing Nickelmane, "But it sounds like... Bullshit. It sounds like bullshit. Excuse my language, but I can't find any other word to describe how idiotic that sounds. I mean, do you really think that I'll believe that Celestia accidentally released a monster?"

"She was most likely trying to seal it, idiot." Nickelmane states, "Celestia doesn't kill. She won't even tell anyone to kill anything. Not even flies."

"Oh, shut up or I'll have you turned female." Dainn snaps.

"At least my name can't change." Nickelmane jokes, "It's gender neutral."

"... Your not wrong, I'll give you that." Dainn says in agreement....

Author's Notes:

Criticism is welcome, though I may rewrite some bits in the future. Tell me what you think! Or leave a comment to leave a comment! That too is apreaciethed!