Spike was reclining in the air, his hands tucked behind his head as his tail lazily swished from side to side. A wrench floated past him. He’d been told a billion times that living in zero gravity too long would affect his growth but switching the artificial gravity off once in a while was just relaxing. Just him, his thoughts, the universe stretching away infinitely outside the ports, and – an alarm went off. Spike sighed. “Welp. Back to work!”

With practiced ease he “swam” through the air towards the door, hitting a button that turned the gravity back on in the main corridors. He landed on his feet and dashed into the cockpit.

He’d left the ship idly scanning the asteroid belt he was parked in, and he had apparently just hit the motherload. A large asteroid dead ahead of him was crammed full of gems. He grinned and hit a large button on the console. The ship began to tractor beam the asteroid in, robotic limbs cutting the gems out and sorting them once it was in the main storage bay. “The check is in the mail!” Spike said proudly. He gave the console a loving pat. “Good work, as always.”

The Elusive Heart may not have been the fanciest scrap hauler in the galaxy, but she always got the job done. She and Spike always made quite the team, and they were all they needed. It’s not like Spike ever got lonely way out in the boonies of the Sol System for months on end…

Spike was pulled out of that depressing thought by a new notification. They were picking up a distress call, from an unknown ship. It had apparently crashed on an asteroid the size of a small moon nearby. This wasn’t Spike’s first rodeo, a distress call could very well be an ambush, but he felt he had a duty to check, especially if someone really did need his help.

He cautiously made his way to wear the signal was being broadcasted from. Breathable atmosphere, which was a plus. His heart sank into his feet at what he saw. “Oh, shit!” he whispered. He definitely recognized that make of ship, he’d had nightmares involving them for almost a year.

It was made of a strange dark grey, organic looking material, had an asymmetrical spiky design, and was full of holes. It was a Changeling scout ship. One pilot only, unless this was an ambush…

The ship had definitely crashed into the asteroid, there didn’t seem to be an occupant in the wreckage. The controls were all wrong, but Spike managed to switch off the distress call after a few tries. He definitely didn’t want any more Changelings showing up. He glanced all around the craft. “Where are you…?” Spike sniffed deeply. It was different smelling than he was used to, but that was definitely blood.

Dragons had evolved on a harsh world and had risen to be the top predators. Although they’d long since moved past the hunting beasts they’d been, some things had stuck, including the ability to track potential prey.

Spike followed his nose, noting a splotch of a thick bright blue liquid on a rock. He stuck his snout slightly closer and sniffed. “Oh. So that’s what their blood looks like…”

He finally found his quarry. The Drone was actually taller than Spike, surprisingly, and rail-thin under the suit he was wearing. From what Spike remembered, all Changelings looked like they were starving, but he’d never seen one up close.

The suit was made of what looked like black rubber, and skintight, it almost looked like a catsuit. The Drone was male, judging by the bulge Spike could make out between his legs, and unconscious. His head had a nasty cut that was still bleeding.

Worried it could still be a ruse, Spike gently poked him in the chest. He didn’t react, but from where spike had touched the suit, a flash of green rippled out in hexagon-shaped cells. “Woah! Cool! And kind of kinky…”

Spike had more reason than most to hate Changelings, but it was obvious that this Drone was injured and in need of assistance. Spike couldn’t just let him die. He sighed. “Faust damnit if Twiley finds out…”

Spike glanced at the Changeling. “Uhh… stay there!” He then dashed back to the Elusive and grabbed a charge. He planted it in the wreckage of the scout ship. Twilight would have killed to get her hands on the technology it had, but Spike had his reasons for this. His ear fins folded down in shame and he grit his teeth. “I’m sorry…” He pressed the button, and the ship went down in flames. Now it couldn’t be traced.

Spike made his way back to the injured Drone, relieved that he was still out cold. He picked him up, slinging one of the Drone’s arms around his neck. Spike was surprised by how light the Changeling was, it was like lifting a feather.

Spike brought the Changeling into what passed as the ship’s med bay, laying him on the table. He briefly considered restraining him in case he woke up but thought better of it. While even an injured Drone could put up a good fight, Spike wanted to give an impression of good will when he woke up.

First things first, Spike went back to the cockpit and punched a random course as far away as he could get without running into anybody just in case the Hive had received the distress call.

He then went back to the “med bay.” Spike took off his jacket and rolled up his sleeves. He didn’t know the first thing about Changeling physiology, Twilight was the expert in Xenobiology, but he prayed it was close enough to treating a Pony. That he could do well.

Knowing there was a high chance he could accidentally kill his patient with medicine not designed for him, Spike carefully used a dermal regenerator on the injuries he could see. He tried to get that strange suit off, but it seemed to be almost welded to the Drone’s flesh. Spike sighed. “You couldn’t have made this easy?” he grumbled.

He pulled over the med scanner to check for internal injuries. The organs were what he’d expect from a pony, and the worst thing he could find was a concussion, which was easily treatable.

Spike prayed to any Draconic, Ponish, or hypothetical Changeling gods who were listening that this would work before he gave the Drone a round of standard antibiotics and a shot to wake him up. Spike then backed away and hid behind a convenient stack of spare parts.

The Drone’s eyes fluttered open. They were a brilliant shade of cyan, and compacted, like an insect’s. He groaned and rubbed his head. He slowly sat up and looked around, a nervous look on his face. “Wy’xeal hi?!” he said in a shocked tone. Like the other Changelings Spike had met, his voice had a buzzing quality, and a slight echo, as if two people were speaking in not quite unison.

Spike discreetly pressed a button on his pad. While the Elusive wasn’t fancy enough to have a true on-board A.I., hopefully the translator could work with Changeish. Which meant the Drone had to talk more.

Mentally preparing for the worst, Spike stepped out of his hiding spot.

The Drone’s jaw dropped at what he saw. A lanky purple dragon with green ridges was dressed in a tan scrap hauler’s jumpsuit. Brilliant emerald eyes watched him carefully. He swallowed nervously. This was it. This was how he died. He cursed the fact he never learned Draconic when he had the chance.

“Do you speak Ponish?” the Drone asked carefully.

Spike blinked in surprise. He then realized it made sense that a Changeling would speak other species’ languages since they infiltrated other worlds.

“Yeah,” he replied. After an awkward pause, he asked, “How are you feeling?”

“Like I crashed and nearly died,” the Drone replied in an equally awkward tone. “Did … you save me?”

Spike nodded. “Yes. I mean, I know Ponies and Changelings are sort of at war, but I couldn’t just leave you there to die.”

“It’s not war,” the Drone muttered.

Spike sighed. “Sorry, I’ve only ever heard the Pony side of it, and I couldn’t think of a better word. ‘Conflict’ I guess… Still not my place to just pass by.”

“You are … a very strange Dragon,” the Changeling muttered.

Spike rubbed the back of his head sheepishly, giving an adorable, embarrassed grin. “Well, I was raised by Ponies, that’s most of it… What’s your name?”

“Thorax.”

“I’m Spike. Spike T. Dragon. My friends call me ‘Spike the Brave and Glorious,’ but as a friend joke.”

Thorax grinned, showing off his fangs. “‘Spike?’” he asked in an amused tone.

Spike sighed. “My sister was like 8 when she named me, nobody told her that wasn’t a typical dragon name.” Spike thought carefully. “I won’t actually go into the Badlands, but I’ll drop you as close as I-”

“I CAN’T GO BACK!” Thorax shouted, terror in his voice and plain across his face.

“Woah! OK! Why not?”

“My M- The Queen kills those who leave the Hive and return. She says they’re ‘corrupted by outside forces.’ I’d like to live, thanks…”

Spike nodded. “Yeah, I can get that. Only problem is if I take you within 3,000 klicks of Equuis Prime, you’d probably be dissected, and I don’t think either of us want that…” Thorax shook his head. Spike sighed. “Is there anywhere else you could go?”

Thorax again shook his head. “I’m pretty much a fugitive…”

Spike sighed. “Well, if nobody finds out about you, I guess you can travel with me for a bit. At least until we find a place you can lie low, it’s a big system… So! Welcome aboard the Elusive Heart, Crewman Thorax! Mi Casa es su Casa, but I expect you to pull your weight. You’re the only other person on the ship, and we can go months without seeing another living soul. Is that all right?”

Thorax smiled. “After what I just left, that sounds great. Thanks. What kind of scrap do you haul?”

An affronted look crossed Spike’s face. “I’m a gem miner, thank you very much! I’m commissioned by the Equestrian Federation and everything! I’m one of the best in the business!”

“Sorry…”

“No problem, it’s an easy mistake to make. I’d better find some quarters for you… C’mon then, I’ll give you the grand tour!”

Spike showed Thorax the cockpit, his incredibly messy quarters, the mess with a basic replicator, and storage. He laughed. “That’s about it, but I hope this will make an OK bedroom for you!” It was a small room, used as a second storage, but it had a broad window, and was tidier than the rest of the ship. Spike blushed. “I’ll have to clear this stuff out, and we’ll have to buy you a bed, the replicator’s food only. Oh, do you have any other, uh, clothes?”

Thorax’s head tilted slightly to the right. “What kind of clothes should I have?”

“Something less conspicuous? Like what a, uh, non-Changeling would wear?”

Thorax nodded. He brought his arm up and apparently typed something directly into the suit he was wearing. The suit shimmered green and morphed into a pink t-shirt and some tan pants. “This is what Ponies wear, right?”

“Woah! That is awesome!”

“Yes, morph-suits are very useful.” Thorax’s eyes widened. “T’lChak!” he apparently swore. “What happened to the ship I was in?!”

“I … kind of blew it up,” Spike said sheepishly. “I didn’t want the Hive to track it or me…”

Thorax sighed in relief. “Is this outfit OK?”

Spike gave him the thumbs up. “You look great! Just need a face to go with it…”

In a burst of green flame, Thorax was replaced by a buff lime-green unicorn with orange eyes, and an orange mane. The outfit had grown to match his new body. “How’s this?”

“Looking good! Are you up to a trip to a trading post to find a bed? I don’t want to make you take the floor.”

“I should be OK,” Thorax said uncertainly. “Are you OK spending Bytes on that?”

“Well, I just got an amazing haul, so once I turn that in, I should be pretty loaded for a bit. A bed’s no trouble, and if there’s anything else, let me know! We’d need to travel to my drop-off point, but we’ll pretend you’re not here then, OK?”

“Sounds good. Oh, call me… Key Lime. I’m a baker from Appleoosa.”

“Can you bake?” Spike asked disbelievingly.

“I’m OK…”

“Can you even eat physical food?”

Thorax nodded with a grin. “It doesn’t give us very much nutrition, but it tastes great, and it’s not like we get fat, so why wouldn’t we? It definitely helps us blend in…”

Spike gave a nervous chuckle. He then realized something. “Oh. You were … kinda dying, out there. Do you want something to eat? Would that help?”

Thorax nodded eagerly. “I’m starving! But then, I’m-”

“Always starving,” Spike finished with him. “Must be a miserable life. Well, I replicate a mean pizza, is that OK?”

Thorax nodded. “I love pizza!”

Spike had to ask, but now wasn’t the best time. “Right.” He folded his arms and grinned. “Which way to the mess, crewman?”

Thorax got it right on the first try. “Wow!” Spike said.

Thorax chuckled. “The Hive is kind of an ever-changing maze, so over time we adapted a really good sense of direction.” He shifted back into his Changeling form, back in the Morph suit as it was apparently called. For being a species of raiders and spies, Changeling technology seemed kind of cool, Spike thought.

“Uh, does the morph suit come off?”

Thorax did the head tilt again. “Yes, but then I’d be naked. Do you want me naked?”

“No!” Spike shouted. “Sorry. When I was examining you, I couldn’t get it off to get a better picture of how injured you were. I was just curious, that’s all.”

Thorax nodded. For being an alien Spike had been raised to hate and fear, the bug-like Equine was actually pretty cut- Spike mentally slapped himself. The last thing he needed at this point in his life was a crush, especially on an enemy of the state. With a fine ass… Spike thought with a sigh. Yeah, he was going to request Thorax not wear anything that provocative around him.

“Any toppings you like?”

“When we eat physical food, we’re omnivores, so meat is fine. I could do with the protein. I definitely can’t break down gems,” he said with a laugh. “I’m not picky, whatever you think would be good.”

“OK, but nobody likes anchovies,” Spike said with a laugh.

“I love anchovies!” Thorax said with a grin.

Spike blinked in surprise. “Me too. One pizza, coming up!” Spike punched an order into the replicator and a pizza whirred into existence. He’d left the gems off since his guest couldn’t even bite into them, and in Spike’s not-so-humble opinion replicated gems tasted like packing peanuts. As part of his payment, he always kept a cut of “snacks” out of what he found.

The pizza was peperoni with anchovies and olives. Spike portioned out half to Thorax who tore into it ravenously.

“Mmm!” Thorax moaned. “So Fli’ken good!” Spike chuckled at the slip into Changeish. “Changelings have an enhanced sense of taste,” Thorax explained, “So I’m getting more out of this than you are. This is amazing!” He wiped a bit of grease off his chin.

Spike chuckled. Okay, Thorax was adorable, that didn’t mean he had a crush on him though!

“You’re not like any Changeling Scout I’ve met,” Spike said.

“I … haven’t been a scout long,” Thorax replied.

There was a long, awkward pause, as they both knew what issue they weren’t talking about. Thorax broke it by pointing at the replicator. “Will you show me how to use that?”

Spike nodded. “You’ll be here for at least a few months, so of course! Can I buy you some clothes in exchange?”

Thorax looked confused. “My morph suit can turn into anything I want, and it’s self-cleaning. Why do I need more clothes?”

“It’s kind of … revealing,” Spike managed to say with a straight face.

Thorax was definitely confused now. “It covers almost 90% of my body. How is that too revealing?”

Hoh, foal. “It … uh, hugs you a little bit too tightly.”

“It isn’t alive, how can it hug me?”

Spike facepalmed. “Yes, it covers you, but it’s so tight you might as well be naked! I can see your ribs! I can see, well never mind, but it’s a bit distracting.”

“My body is distracting to you?”

“Very,” Spike sighed.

Thorax shrugged and punched another code into his suit. It changed back into a shirt and pants. “Is this better?”

Spike nodded.

“Strange…” Thorax muttered, going back to his pizza. “If you don’t want the default form of the suit, I will happily wear clothes you get me, but we’d need a few sizes and body types probably…”

“Should be manageable.”

“Are you this generous to all your stowaways?”

Spike chuckled. “Nah, I just … haven’t had company in a while. We can leave to drop off my haul and go shopping for you whenever you’re ready!”

Thorax nodded, and they set off.

“Key Lime” was in awe at the bazar around him. It was a major trading hub for the entire system, anything you wanted could be found for the right price. Even if it wasn’t entire legal, but that section was deep below the surface. Spike and Thorax were sticking to above board sales today.

Thorax had to stop himself from purring as he tested each mattress, each seemed better than the last! They were testing things for beds in star craft since gravity could be unpredictable at times. They finally found a mattress and frame Thorax loved, and even got a decent price to install it!

Next was clothes shopping. Thorax’s siblings had always poked fun at him for it, but he had enjoyed playing “dress up” as a nymph. When practicing a disguise, one of his favorite parts was creating a matching outfit.

They got a number of outfits in different styles and sizes, since Thorax assured Spike he could adjust his measurements to fit, rather than the other way around.

Spike insisted on buying underwear for each outfit, although he didn’t want Thorax to model those for him. At least outside of his head. His eyes caught a pair of sinfully red lace panties that were in Thorax’s size in his true form.

Spike’s heart began to thud in his chest, and he could feel a flop sweat starting as his mind conjured Thorax in them, lying in a silky bed with a cute expression. No. Absolutely not! It would be wrong to get them for the Changeling just because. He was the Captain, Thorax was his crew, and this wasn’t Space Trek for Faust’s sake!

Spike snatched them anyway. They were about his size. Since he certainly wasn’t going to give them to Thorax, he might look good in them. It wouldn’t be his first time. Maybe he could get a date the next time he was in the civilized sectors.

Thorax loved each and every outfit Spike helped him pick out, promising to find a fun face for each. He obviously didn’t have Bytes to repay the drake, so he opted for a bone-crushing hug, joy lighting up his face. Spike realized that this was probably the nicest anyone had ever been to the Drone.

They had a nice lunch in the food layer, and Spike introduced Thorax to some foods the Changeling had never heard of. The Changeling was surprisingly not picky, seeming to enjoy everything he tried, though he went meat free in his current form. Spike had to remind himself that these weren’t what the Changeling really wanted, and that on some level, the Drone saw him as a snack.

Spike’s pad pinged to let them know Thorax’s new room was installed, and they rushed to see it. Thorax’s jaw dropped. The former storage space had been converted into a cozy if small bedroom in soothing colors. Thorax carefully reached out towards the bed as if he were afraid he’d spook it, and gave it a quick pat. “I – I’ve never had one before…” he whispered.

“A bed to yourself?”

“A bed. A door. A room that wasn’t crammed full of Drones trying to stay warm. This is … thank you.”

Spike discovered that day that a Changeling could cry from happiness while not disguised.

The trip to the bazar was brief and unusual, business never really stopped for Spike. Well, Spike and Company now. He enjoyed speaking to Thorax, but it was painfully obvious that there were certain subjects they were dancing around. Neither of them ever mentioned family, or the Wedding…

Spike had broken down and asked if Thorax would be able to properly feed, since Spike didn’t love him, and wasn’t about to let him drain an innocent soul. Thorax patiently explained that Changelings could feed on any positive emotion, love was just the strongest and most filing. There were also lots of different types of love, each meaning different things. Thorax admitted with a blush that he’d actually been simply feeding on Spike’s love for his ship and his work. It didn’t have to be romantic love; love of life was love too. Spike hadn’t noticed Thorax’s snacking on him at all, but he wasn’t any worse for wear, so he was OK letting things stand where they were.

Spike didn’t know if it was an inherent trait of Changelings, but Thorax was a very fast study. He’d picked up how to fly the ship at lightning speeds, and now he could fly the Elusive Heart almost as well as Spike! Almost.

The two males were sitting in the cockpit as it idly scanned a new section of asteroid belt for anything they could harvest.

Thorax sighed. He was fidgeting slightly, Spike noticed. “What’s up?”

Thorax cringed. “Kinda bored,” he admitted slowly, as though it were something shameful.

“Why the tone of voice?”

Thorax looked at him with wide eyes. “You’ve given me so much! A home, a bedroom, companionship, your love, and a career! My being bored with my work is an insult to your gift!”

Spike chuckled. “Thorax, it’s fine! Gem mining is pretty mind-numbing at times, it’s OK if you’re bored once in a while.” Thorax relaxed slightly. “I’ve got some comics in my quarters if you want something to read while we wait.”

“Comics?” Thorax asked in confusion.

Spike chuckled. “Oh, are you in for a treat! Just go find something that peaks your interest, I’m sure you’ll find something to amuse yourself.”

Thorax nodded and headed off. Spike chuckled; he was happy to be the one to introduce Thorax to the wonderful old-fashioned medium of the graphic novel. Spike ran through a mental catalogue of what he had on board.

Spike chuckled a bit. Years of living with Twilight had rubbed off on him, but while he was by no means a slob, his quarters weren’t quite as fastidiously tidy as Thorax’s. The color drained from Spike’s face, and he let out a very rude word in Draconic as he remembered something important when it wasn’t just him on board. He ran as fast as he could.

Thorax was a bit nervous at entering Spike’s room. While Spike was a very “chill” person, years of habit made him wary of entering the room of a superior, even with their permission. He closed his eyes and grit his teeth, forcing memories back down. “You’re not here, you’re not here, you’re not here,” he mumbled almost as a mantra. The anxiety drained out of his arms, legs, and wings, and with a sigh of relief he headed in.

Thorax had no idea what comics were, but he had a feeling he’d know them when he saw them. Next to Spike’s bed was a small bookcase, stuffed to almost double capacity. While books were arguably outmoded, they were by no means dead. Maybe a comic was a genera of book? He thumbed through the shelves. Some of the books were much thinner than the others, and softback, with … pictures? No, they were mostly pictures. It seemed these were the comics Spike had recommended to him.

Thorax pulled a comic at random off the shelf and gave it a quick glance. He chuckled. These were definitely something Spike would enjoy… He could give them a try. As he went to find the next issue, something fell off the shelf. It looked like a magazine. Figuring it was another comic, Thorax cracked it open.

Oh. Oh, stars, this wasn’t a comic! A prerecorded hologram of a beautiful gryphon tom flared to life in front of Thorax’s eyes, as the male spouted fairly cheesy dialogue. Thorax had to admit he was handsome; he could see the attraction.

Thorax turned around, and his ears fell. Standing in the doorway, his face several shades lighter, his expression that of someone who swallowed a lemon, Spike stood in burning shame. It radiated off of him in waves. Thorax was confused. There was certainly an accidental invasion of privacy on his part, but why was Spike feeling that way?

Thorax snapped the risqué issue shut, shutting off the hologram. He puzzled for a few minutes. When he looked back up, Spike seemed to be praying in Draconic, his eyes closed. Thorax had it figured out. As kind as Spike had been, he was still a dragon, so Thorax approached him carefully. “Spike?” the Changeling asked with concern. Spike didn’t respond. Thorax put his hand under Spike’s chin and tilted Spike’s head up so the shorter male was making eye contact with him.

“Uh. Hey. So, about that…”

“I like males too,” Thorax said simply. “He was gorgeous. I can understand being, uh, lonely out here, I’m sorry for invading your privacy. I won’t do so again.”

Spike blinked in surprise. Thorax was … gay? The guy he had a mad crush on, could maybe like him back? No, this was just the universe toying with him. Any second now he’d wake up.

Thorax was speaking again, a hurt look on his face, not because of Spike, but for Spike. “I am sorry others made you feel like less for liking males,” he said.

“What?! NO!” Spike shouted. “I mean, yeah, some of the ponies growing up could be pretty homophobic, but I didn’t give a shit about that. My family are all super-supportive, which is awesome. My adoptive Mom keeps asking when I’ll bring a cute guy home,” Spike said, a blush showing through his scales. “It was just…”

“Me,” Thorax said simply.

The tattoo of Spike’s heart trying to escape his chest began again. Why did he have to be such a nervous wreck?! Shit. Did Thorax know?! No, there was no way, Spike had been incredibly careful around the Drone. He’s a Changeling, he can literally sense your emotions, how could he not know?!!! Spike mentally screamed at himself.

Before either of them could get a word out, an alarm began to blare through the ship. Thorax’s ears swiveled as he analyzed the sound. “I don’t recognize that one,” he said slowly.

“Diamond Dogs,” Spike said. He grabbed Thorax’s shirt front and pulled him as hard as he could to the front of the ship. “Have you met Diamond Dogs?” he asked.

“Many times,” Thorax hissed, his eyes narrowed, his fangs on display, and his tongue sticking out angrily. Spike shivered. He hadn’t seen Thorax angry before, he was honestly kind of scary.

“OK, so you’ll know we’re outgunned, and have no way of knowing where they are.”

Diamond Dogs were a species of scavengers and slavers, but they had a technology they’d “acquired” that put them leaps and bounds ahead of the rest of the system. It allowed their ships to tunnel through subspace, allowing them to hide and burst out at random before they quickly hid again. They would swarm larger ships and overwhelm them without taking a single hit. No one had ever managed to land a hit on a Diamond Dog Cart, despite any bragging claims to the contrary. They were one of the main banes of miners’ and scappers’ existences.

Thorax fired up the weapons system. “Thorax, you can’t hit something you can’t se-”

Time seemed to almost slow down. With almost mechanical precision, Thorax somehow predicted exactly where each Cart would appear from, landing a shot that disabled their power. Interestingly, he seemed to be more focused on simply disabling the Carts than inflicting serious damage. Spike’s jaw dropped. Shining couldn’t shoot that well, it was impossible!

Within moments, Thorax had disabled the entire ambush they’d walked into. The Drone stood up, shaking with fury and gave the ships the Finger, a universal symbol. “Rey’ax Ca’al tu Von Baug!” Thorax screamed. He sat down and smiled. “Ha! Re’sei neir tal uur, Pharynx?!!” he said, apparently speaking to his memories.

Thorax then hit the drive, steering them well out of the way of trouble.

Spike cleared his throat. “How … how did you do that?!”

Thorax looked at the young drake with a fearful expression. “I – I’m not a Scout,” he whispered.

“No shit!” Spike snarked.

“I’m the youngest broodson of the Queen, and second heir to the Hive. I don’t like combat, but I can hold my own.” Thorax wasn’t looking at Spike as he whispered with horror, “And I led the Invasion on Canterlot.”

Author's Note

Don't worry, plenty more to come, but that was a good cliffhanger to pause on. Bwa-ha-ha!
Hope you get some enjoyment out of this!
For a bit of worldbuilding explanation the 3 tribes of ponies all developed on seperate worlds in the same star system, along with all the other MLP species, like Dragons and Changelings. While each originally devleoped on a seperate world, the Sol System is more-or-less unified under the Equestrian Federation. The Badlands are a dangerous asteroid belt even scrap-haulers and miners stay well away from.
Spike will explain his adoption story next chapter, BTW. Thorax isn't the only one with family secrets...

Quick translation for when Thorax slipped into Changeish:
"Wy’xeal hi?!" - "What the Hell?!"
"Fli’ken" - I'm not translating that... use your imagination...
“Rey’ax Ca’al tu Von Baug!” - ancient Changeish Warcry.
"Re’sei neir tal uur, Pharynx?!!" - "Who's the lousy shot now, Pharynx?!!"