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The Shape of Chimera Sui Generis.

Chapter Text

Silas M. stood stock-still, frozen in the woods.

The morning was clear, a little over-warm for the time of day, and the bright sunshine spilling down through the treetops made the scene he was seeing look even more bizarre, something removed and put somewhere it shouldn’t be.

There was…something, a very big something, sitting hunched over on the trunk of a fallen tree, and he…couldn’t make sense of it.

Silas had just wanted to go for a hike. He’d even come out early, so he’d have the trails a little more to himself.

It was Cthulhu, sitting on that tree trunk.

Well, perhaps not quite, but it was a massive creature with an octopus head! Afraid to move in any direction lest the creature hear him, Silas just watched it through the bushes between them.

He’d been hearing about all those alien heroes on the news lately. They’d been popping up all over, saving shopping malls from robbery or stopping schoolbuses full of frightened children, or so they’d said- so maybe…hopefully? This was just…one of those.


The creature didn’t look like one of the aliens he recognized. There was a lizard-like one, blue-striped and very fast, and Silas had also seen a fire-powered one and something with four huge arms, but never an octopus. A very, very big octopus.

The octopus creature was a pale green, with some darker mottling on the tentacles surrounding its face, and its eyes were shiny and red, lacking visible pupil or iris. Its arms were overlong for its body, distinct cords of muscle all wound up around each other, with the ends of metal caps jutting out in odd places. It had two huge, four-clawed hands, and these were clasped together, the creature staring at the ground.

Or glaring. Not to ascribe human facial expressions to something inhuman, but that octopus looked kind of fucking pissed.

Silas had just calmed down enough to really study the thing when it spoke.

“What are you looking at?”

It didn’t turn its head, or really even move at all, but Silas jumped about a foot in the air regardless, letting out an entirely involuntary squawk. The creature’s voice was a heavy rasp, and it did indeed sound pretty pissed.

“Sorry!” Silas blurted. If by some miracle the octo-person had been talking to someone else, it certainly knew he was here now.

There were a few beats of deeply uncomfortable silence.


“Uh, you’re really cool-”



A heavy pause. Now the creature was looking at him, its head turned and red eyes narrowed. Without bothering to be discreet, it peered over the chest-high brush between them and gave Silas a distinctly unimpressed once-over. Silas flushed with embarrassment despite himself.

After the uncomfortable glaring, the octopus creature rolled a shoulder in what could have been a shrug and seemed to decide that its visitor was not only not a threat, but not even worth paying any more attention to. It went back to gazing at the ground, scuffing up some grass with a clawed foot.

Silas struggled to calm himself, emboldened by the lack of physical aggression on the creature’s part.

“What’s…your name?” he slowly asked, dipping his head and avoiding the creature’s eyes, but still watching it through his lashes. The creature stayed irritably silent and didn’t even look at him, so Silas added on, “My, my name’s Silas.”

“I don’t care. Get out of here before I lose my temper.”

Alright, that was a clear enough warning, and Silas clamped down on any further questions, starting to back up and turn away for the sake of his very vulnerable body, when the creature made a harsh sound and bent in on itself. It wasn’t quite doubled over, but it did appear to be in distress, and the few seconds it took to compose itself were enough for Silas to take his concern as an excuse to stick around.

“Oh, shit, are you okay?”

“Fuck off,” the creature replied as Silas tried to approach it again. Its hand was pressed against its abdomen, and although Silas was out of range, it even took a swipe at him when he tried to speak up again.

“I just- hey! Jesus, shit, I just want to help.”

At that, the creature barked a laugh.

“No you don’t.”

“Yes I, yes I do!” Silas stammered. He was trying to find the correct tone for this situation, worried the thing was hurt or bleeding but sensing it would not tolerate any sort of pitying. “Are you hurt…?”


“…Are you just saying that so I’ll leave?”

“You’ll leave if you know what’s good for you!” the creature snapped, and Silas automatically raised his hands, taking a few steps back. The creature just glared at him.

“You don’t have to be so aggressive. I was just trying to make sure your organs weren’t spilling out or, or something.”

Silas had always wanted to make friends with a big, cool monster. The one chance he’d probably ever get, and it wouldn’t even tolerate him! That stung more than just a little bit.

The creature bared its pointed teeth at him.

Silas stayed put.

For a long minute, the two were at an impasse, Silas barely managing to hold his ground in the face of something with hands bigger than his head, and the creature very slowly dropping its grimace as it looked Silas over once again, and then a third time. It settled on a mildly aggravated frown.

Silas heaved a sigh.

“… …It’s Vilgax.”

“Uh- what?”

Vilgax, the creature repeated, folding its arms across its chest, crossing an ankle over its knee, “My name.”

It seemed annoyed, but no longer hostile, so Silas relaxed enough to chance a smile, leaning forward a little.

“Oh. Well, it’s nice to meet you, Vilgax.” he said. “I’m sorry I bothered you. It’s just, I’ve never gotten to meet someone like you before. You know…?”

“An alien.”

“Yes! So you really are?”

There were so many more questions to be asked- about intergalactic travel, about his species, about his home planet and interplanetary relations- but Vilgax didn’t seem like he’d be willing to entertain them, so Silas wasn’t going to continue to press his luck.

Vilgax snorted, an impressive feat given his lack of a nose.

“What else would I be?”

Silas shrugged.

“Don’t want to assume.”

The two went quiet again. Shifting awkwardly from foot to foot, Silas adjusted his backpack where it hung on his shoulders, now feeling too heavy despite its light contents.

“Do you mind if I sit down?” he asked, and Vilgax waved a hand dismissively. He didn’t seem to want to talk. Silas found a patch of grass just a few feet away in the shade, and settled down, facing his new acquaintance with his back to a tree.

Trying not to stare, Silas studied him. Very big claws. Yellow teeth, thin and sharp, poking out through black lips. His breath rumbled when he exhaled.

The two sat in silence like this for a few minutes this time, Silas trying to commit Vilgax to memory while Vilgax glanced around dispassionately and made a point of not looking at him, and Silas eventually grew bored and turned his attention to his backpack.

He pulled out a water bottle, took a swig, and then sloshed it gently.

“Water?” he offered.

For the first time, Vilgax appeared vaguely interested. He seemed to consider for a moment, looking at Silas with great suspicion, before he huffed and stretched out a hand. Silas handed it over, a little bit in awe of the size of Vilgax’s claws.

Vilgax tipped his head back and poured the entire bottle over his face.


He supposed that should have been expected.

Once the bottle was empty, Vilgax crumpled it in his hand and tossed it aside without so much as a ‘thank you’, which was also unsurprising. Silas made a mental note to pick it up later.

“Sooo…um, what are you doing here, Vilgax? If you don’t mind me asking.”

“I do mind,” Vilgax replied, but continued anyway, “But I have some…unfinished business here on Earth. Nothing that concerns you, I’m sure.”

Silas looked around. They were completely alone, far up on a hiking trail in a small Washington forest.

“And that’s happening here?” he asked.

“Of course not.”

Not further explanation came. Silas pursed his lips, and sat up on his knees.

“So why are you on a tree trunk, then?” he prompted. He was still unconvinced that everything was well and good with the situation, especially considering that Vilgax showed a marked reluctance to stand up and walk away from Silas’s pestering.

Vilgax didn’t have anything in the way of normal eyes, but the toss of his head indicated some heavy rolling anyway.

“It is none of your business, boy, and you are grating on my nerves…”

Silas raised his eyebrows, leaning forward.


A heavy sigh.

“But, since I will apparently not be rid of you, my ship has crashed, and it’s my time of the decade. I’m in no fit state to repair it.”

Vilgax sounded very bitter about this information.

“So unless you know how to fix a spacecraft, that is enough questions.”

Silas was quiet for a beat. No, he didn’t know how to fix a spaceship- or even a car, for that matter, but another question was already burning at the back of his throat, and he made a groaning sound, aware he was walking a thin line by bludgeoning the alien with questions. Vilgax shot him a dangerous look.

“–Okay, one more question I promise, and then if I can’t help you I’ll leave you alone, I swear,” Silas promised, and Vilgax dragged a hand down his face in aggravation, leaning forward to get in Silas’s face.

One. More. Make it count.”

“What did you mean, time of the decade?” Silas asked immediately. Vilgax looked at him as though he were an idiot.

“I’m not teaching human larvae about my mating cycles.”
he said, his teeth showing in a sneer. The contempt in his voice could have burned.

“I am not a larva. I’m a grown-ass adult.”

Mating cycles…mating cycles? So, probably like a heat, then, like dogs and cats got? This information actually raised more questions than it answered, not the least of which being, how do you do that, but very abruptly now Vilgax had stood up, his full height putting the fear of god into Silas, who was still on the ground. This guy was like, ten feet tall! At least!

“Oh, jesus,” Silas yelped, scrambling backwards on his hands. “I’m sorry! Dude- Vilgax- please don’t eat me.”

Vilgax just gave him another scathing look. Without further conversation, without even a goodbye, he turned away and just walked off, muttering rude things to himself, flattening vegetation and shouldering branches off of trees. He was really leaving for good? Words caught on his own tongue, Silas stammered over himself until Vilgax was nearly out of sight, finally calling after him in a near-shout,

“Wait! Wait, wait- maybe, maybe I can help you!”

This might be the only alien-lovin’ chance his little gay self ever got!

… … …At least that stopped him. Vilgax reappeared through the trees with disbelief writ large on his face, and for a good minute Silas felt himself wishing the ground would just open up and swallow him, a horrified flush sweeping down his neck.

Not that he didn’t mean it. Vilgax was monstrous, sharp-toothed and clawed, arms as big as someone’s torso, and with the evident strength to throw Silas over his shoulder like a ragdoll– basically, like, a total babe. There was just probably a smoother way for him to have said that.

Silas alternated between staring at the ground and glancing up at Vilgax, mortified, as the immense alien re-approached.

Silas took a minute to cover his face with his hands, and when he looked up again, Vilgax was crouched down directly in front of him, less than a foot away. Silas barely suppressed his screech.

“Uh- huh, hey,”

Vilgax was just staring at him. Not angry, at least no more than usual, but they were definitely in each others’ personal space and the lack of a reply was very uncomfortable. Silas was too intimidated to do anything, so he just stared back.

“… …That’s not a joke you want to make. Vilgax spoke up eventually. One hand pressed to his chest, feeling his own thudding heartbeat, Silas shook his head, a little frightened but also kind of a little bit turned on.

“It’s not! It’s not a joke. I’ll- um.” Oh, jeez, his voice was coming out squeaky. “I’d be happy to help you! With…your…uh, your cycle, if, if, if you want.”

Doing a pretty good impression of raising an eyebrow, Vilgax looked Silas up and down, very slowly…and then showed his teeth. It appeared to be an attempt at a smile.

“You are one lucky, lucky human,” Vilgax informed him, sounding almost thoughtful as he reached out and grabbed Silas’s wrist, hauling him to his feet. Silas smiled back at him, nervous and eager.

“So is that a yes?”

“Yes. You had better be prepared for what you’re getting into.”

Chapter Text

Silas was maybe not prepared, but certainly ready and willing. Eagerly following Vilgax, whose single stride took two of Silas's, the young man left his hiking gear behind to be collected at a later date- there were much more important matters to attend to now.

"Are we going to your ship?" Silas asked, huffing from trying to keep up.


A man of few words, apparently. Silas might have to lay down some ground rules for proper communication during sex...thankfully, however, the ship wasn't too far, sparing Silas another tense silence as he saw the vessel over the tops of the trees.

"Whoa, is that it? Oh my god. That's bigger than my house. Is it just you in there?"

"Yes. Hurry up."

A little rude. Ground rules, then, definitely.

As they approached the door to the ship, Silas sped up to stick close to Vilgax, a little nervous to see the inside of this place and feeling more comfortable tucked up close to his enormous new soon-to-be lover. Vilgax looked down at him, and waved him inside. The door slid shut behind them.

To Silas's relief, the ship's interior wasn't really very outlandish at all. Mostly metal, with nothing in the way of decoration- just a wall of computer screens in front of a panel of controls. A few seats, here and there. Blank shiny flooring. Silas took a minute to spin around and look at everything, letting Vilgax move away from him to do whatever he might need to do before they got into things.

"So...uh, do you have a bed? Or like, a mat or something?" he asked, bending down to look at a disc-shaped robot hovering nearby. He heard faint rustling behind him.

"Yes. But we're going to want to do this on the floor."

Silas glanced back.

"Why-? Oh, christ! Would you- would you warn a guy?" he squawked, and slapped a hand over his eyes, peering out between his fingers despite himself. Apparently unperturbed, Vilgax just stood there with his arms crossed, the leotard-like clothing he'd been wearing nowhere to be seen. The boots were still on.

"I tire of waiting. It's been two earth days for me," he said bluntly. "I am crawling out of my skin."

Okay, very sudden, kind of embarrassing...but understandable. Silas sighed and uncovered his face, trying not to stare too hard just yet.

"Alright, I get it...a little foreplay would have been appreciated," he said. But, hell. He was raring to discover what this guy was packing, anyway. Evidently picking up on Silas's eagerness, Vilgax motioned him over to him and moved to the side, making another sharp attempt at a smile (though it was much more intimidating than reassuring).

"You will get your reciprocation, boy, rest assured."

"It's Silas."


Reciprocation did sound nice, though.

", what should I-?"

"Come here."

As he spoke, Vilgax leaned heavily against the wall and slid down to sit, patting his bare thigh. Despite his efforts to appear even a little collected, Silas hurried over to him with barely-contained enthusiasm. He crouched down next to him with a flush.

"So. Ahem. What'cha packin', big guy?" He shot Vilgax a smile, hoping to get him to let his guard down, a little- and was rewarded with a short bark of laughter as Vilgax shifted his weight. Spreading his legs to give himself some room, he reached down and ran the pad of a finger over what had appeared to be a flat expanse of skin, which Silas now saw was a very thin slit. As Silas watched, thrilled, Vilgax carefully parted this slit, mindful of his own claws, and Silas saw the tip of something slick and red start peeking out.

"Oh! You have a cloaca?" he asked, now delighted. Vilgax appeared, almost- a little embarrassed? That was nearly sweet.


Silas moved his hand to hover over Vilgax's thigh.

"May I-?"

"By all means."

Being perhaps more gentle than he needed to be with someone Vilgax's size, Silas braced one hand against Vilgax's leg, the other palm to the floor, as he leaned in for a closer inspection. The edges of his cloaca were very thin, really nothing like the lips of a vagina, but what little flesh Silas could see inside was an almost cherry red, including whatever was swelling to poke out as he looked over it.

"...Can I touch?"

"You don't need to ask."

He was always going to ask (it's only good manners), but that was a conversation they could have a little later. Cautiously, Silas ran the pad of his thumb over the slit.

Vilgax made no sound, and Silas repeated his gesture as the swollen thing inside his cloaca finally began to slide out in full- nothing so strange he couldn't handle it! Based on general wasn't unrecognizable as a dick, although it, too, was that bright red color, and was a bit short and wide, with an odd round bulge in the middle. It tapered to a soft point, with the flesh at the end looking all twisted around itself, like Vilgax's arms.

Excited, Silas looked up at Vilgax for permission, and got a nod in return.

"Tell me if I do something you don't like." he said. "Is there- is there anything in particular I should do?"

Vilgax groaned, sounding very impatient.

"Anything. I don't care. Anything that humans do."

Silas snorted.


Scooting around to kneel properly between Vilgax's legs, Silas gently ran his palm up the underside of his cock, and when it didn't burn his skin to touch, he took the base in his hand and moved over it in a slow drag. Something about the texture of its surface was familiar- maybe almost gelatinous? Firm, but with more give to it than he'd expected.

Vilgax exhaled in a long sigh.

"Good. Good."

His claws were tapping the floor where he'd rested them, and Silas laughed warmly.

"You've been really pent-up, huh?" he asked. He stroked him slowly again, not expecting an answer, and watched fluid bead on the skin under his hands, not just on the tip but all over the thing. Unlike in a human, Vilgax remained cool to the touch.

"You have no idea."

Silas pursed his lips thoughtfully.

"Vilgax..." he prompted, rubbing his thumb along the bulge in the middle of his cock, making sure he had his attention before continuing. Vilgax met his gaze questioningly.

"Hm. Can I use my mouth? Do you think that would be okay?"

For just a moment, Vilgax hesitated.

"...All of your teeth are blunt?"

"Oh, yes, of course! Besides, I'm not going to bite you. Is this not a thing where you're from?" Silas asked. He squeezed, very gently, and watched Vilgax's legs twitch.

"No. My teeth are for tearing meat. That would be ill-advised."

Yeah, he could see how that could be dangerous. Apparently decided, however, Vilgax tapped Silas's forehead to get his attention and waved him on.

"Go ahead then. No teeth."

"No teeth," Silas promised. Hopefully there was nothing dangerous about getting this mess in his mouth...

Deciding a little bit of danger was worth giving an alien a blowjob, Silas leaned down, bracing an elbow comfortably against Vilgax's leg, and took just his tip into his mouth. To his surprise, Vilgax shuddered.

"You're- warm. Yes, you're a mammal, of course," he muttered, more to himself than to Silas. He let his head tip back to rest against the wall, and Silas took this as permission to continue. He took Vilgax in a little deeper, as well as he could, now wondering how exactly he was going to deal with that much wider bulge just a ways down, and trying his best to move his tongue along the underside of the cock in his mouth. To be honest, he was pretty clumsy by human standards. But it seemed to be working for his particular partner.

The tapping of Vilgax's claws against the floor increased in volume with every suck and slight scrape of teeth.

"I'm- ungh. My climax approaches, be aware..."


"Yes, already!" Vilgax let out a heavy huff. It seemed he really wasn't exaggerating, because his legs were beginning to twitch, much to Silas's surprise. "My stamina will increase- once I have a few, under my belt."

Tickled by how quickly he'd managed to get Vilgax to this point, Silas pulled off, getting him a startled and understandably frustrated look.

"Until I know what's gonna happen, I don't want you coming in my mouth," Silas explained. "Hang on, okay? Just, stop me if you need to."

Now Silas shifted a little bit, leaning off to the side, eager to see exactly what was going to happen but aware of the need to be careful. He took Vilgax into his hand again, and bent down low to the floor.

"Can I lick your- um, here?"

Gingerly, Silas brushed a finger along Vilgax's slit, where there were a few inches of space underneath where his length emerged. He'd always liked eating pussy, and while there were some decided differences, he was more than willing to try. Vilgax made a quiet sound in his throat that was definitely a moan.

"Yes. Do it," he urged. Silas fought down a smile. What a wonderful surprise, at odds with his new partner's otherwise surly demeanor- then again, it's always fun getting oral for the first time!

"Okay. Easy, big guy," Silas said quietly, and tilted his head, pressing what was almost an open-mouthed kiss to the few inches of open cloaca he could reach. He let his tongue smooth over it once, and then there was a huge clawed hand on the back of his neck, not pushing but simply resting there. He smiled despite himself.

Unwilling to pull away from his task to give verbal praise, Silas simply hummed every now and again, working very hard to keep himself focused on still stroking Vilgax's cock in earnest as he licked and sucked him, the taste of him quite salty but otherwise not unpleasant. Vilgax's length had grown very, very slick.

"Ye-es, yes, keep that up," Vilgax encouraged him, lightly scraping his claws up and down the skin of Silas's neck. The sounds he was making were like a punch of arousal to the gut, and Silas shifted in place, becoming more and more aware of how much he would like that reciprocation he'd been promised after this. Not that he wasn't enjoying this part!

After a minute of debate with himself, Silas moved his mouth back to Vilgax's cock, sucking at the base of it and hopefully out of the way of whatever kind of orgasm was going to happen. His free hand he slid down, rubbing gentle circles over his partner's now-wet slit, and he dared to dip his middle finger inside, just a little bit as he waited to gauge Vilgax's reaction.

Vilgax made a very approving sound.

"You are a wicked thing," he told Silas, in a tone that was definitely praise, and the pinch of claws on the nape of his neck only made Silas all the more pleased with himself. He pressed his middle finger in deeper, to rub against the soft flesh inside Vilgax's cloaca.

A last, open-mouthed suck against the side of his dick, and Vilgax went taut as a bowstring. He didn't groan- in fact, he went completely silent, save for a sharp gasp of breath, and he hurriedly pulled his hand off the back of Silas's neck as his cock started to twitch and pulse. The reason for moving became apparent as his claws dug slices into the flooring, puncturing metal- and Silas became very glad that Vilgax had the presence of mind not to carve through his much smaller partner like butter.

Silas crooked his finger once, twice, and Vilgax hunched over him almost alarmingly, although it afforded Silas an amazing view of his face when he glanced up. Vilgax came silently, with his teeth clamped, and Silas jerked him through it, watching with great interest as the swollen bulge on his cock smoothed out with his orgasm, a huge mess of clear, watery substance streaking the polished floor between his legs and narrowly missing Silas. Vilgax did not relax until he was completely spent, leaning back hard against the wall.

Silas finally pulled away to grin at him, quite wet between his own legs and oh-so-pleased with himself.

"Good? You okay?"


"Aaand...that's why you do this on the floor, huh?" Silas asked, scooting over and out of the way of the mess to lean against the wall as well.

Vilgax sighed heavily, and did not reply.