Dragon Size

Just a quick note before this story begins, Toothless will be Anthro here.

Another day, another workout, and another attempt for our auburn-haired, green eyed boy to get make himself bigger.

It all began a month ago when Hiccup looked at himself in the mirror and frowned upon the pencil thin complexion that he's always had and decided it was time for him to do something about it, so he signed up for a membership at a local gym and was given one of the biggest and strongest physical trainers that the gym had to offer, a black dragon named Toothless.

When Hiccup first saw Toothless, he was certain that the dragon was part bison as he was just that massive. The giant dragon had to have been at least 14 feet tall and each part of his body was rippling with muscles so densely packed that Hiccup could probably walk on them to no ill effect.

Even more astounding was the bulge that was just barely contained by the red XXXXXXL jockstrap that Toothless always seemed to wear. Many dreams in the following month was that of said jockstrap being ripped open to reveal what must be a cock big enough to swallow Hiccup's 5 foot figure whole.

From that day on, Hiccup did what he could and listened to everything that Toothless told him about proper exercise forms and routines, despite being very easily distracted by the hunk of a hunk dragon.

And despite all the effort Hiccup had put in in the past month, seeing working out an hour a day, 4 days a week, Hiccup still found himself as pencil-thin as ever.

That's what takes us to this day as Hiccup was finishing up the last set of the last exercise for the day, some bench presses. Toothless was spotting Hiccup and helping to make sure he didn't hurt himself, but given Toothless's gargantuan size and the height of the bench Hiccup was laying on, there wasn't much to help Toothless's massive bulge pressing against Hiccup's head as he went along, giving Hiccup a very familiar stir in his lower region.

Hiccup did his best to concentrate on the iron bar in his hands, which were only set to 45 pounds, and Toothless kept count of the reps Hiccup was putting in saying, "…7…8…9…come on, Hiccup, one more and you're done…" Hiccup takes a few more breaths before pushing up on the barbell until his hands were just above the rack that the bar sits on when not in use before Toothless helps him put the bar back on the rack. "And that's 10. Nice work, Hiccup, that should do it for the day."

Hiccup lets out a deep exhale of relief as he was glad it was over. He takes a huge glug from the blue reusable water bottle he brought and says, "Fuck, I thought that would never end!"

Toothless nods to that. "Yes, you did seem to struggle a bit, but the fact is you did it. Come on, lets go get you out of those sweaty clothes." Toothless refers to the brown gym shorts that Hiccup was wearing.

The two of them make their way into the gym's men's locker room, the entrance of which recently had to be upsized due to Toothless being there. The room was empty as this was a time of day when hardly anyone was at the gym, a time that Hiccup enjoyed as he wasn't sure how people would react to seeing a boy of his figure working out, it could be a bit humiliating to see him barely lift the lightweight stuff.

Hiccup plops down on a bench in front of his locker before sighing deep. He raises his arm in a curl position and gives his bicep, or what would be a bicep, a poke before sighing again. "Man, seems like this whole working out thing isn't really working out."

Toothless glances back as he hoists his 6XL red shirt onto his left shoulder saying, "Hey, you can lift 5 pounds more than when you started, that's something."

Hiccup sighs again. "Yeah, but it's been a month already. At this rate I'll never be as strong as you."

Toothless tries his best to hold back a chuckle out of respect for Hiccup's feelings. "Not to make you feel any worse, Hiccup, but you can't exactly expect yourself to look like me. Genetically speaking, dragons are simply bigger and stronger than humans, can't do too much about that.

Besides, being this huge isn't as glamorous as it may seem. Finding clothes that fit is near impossible, I have to go to this online clothing shop for really large men, I've been on planes where I need to buy 2 seats to accommodate me."

Hiccup raises a brow to that. "Uh, aren't you a dragon? Can't you just use your own wings?"

Toothless chuckles to that. "Actually, I've gotten so big and heavy that my wings are more for show at this point, which brings me back to my original point. I know I look good, but all this can be a bit of a hassle at times."

Hiccup drops his head down to just above his knees. "Still, I just wish there was something else I could do, something to help me get bigger faster."

Even without having to kneel down to see his eyes, Toothless could see how disappointed in himself Hiccup was feeling. Toothless puts a hand on his chin and thinks for a moment before remembering something. "Well…there is one thing we could try. It's a bit of a drastic measure, but it could help you get the body you want."

With this, Hiccup raises his head back up to meet Toothless's eyes and states, "Whatever it is, I'll do it!"

Toothless nods and turns around before reaching into his locker to grab something. From the metal locker, the giant dragon pulls out a grey plastic bottle that he gives to Hiccup. "Here, try this. It's a bit experimental because I haven't had anyone try it, but who knows?"

Hiccup opens up the bottle and finds an off-white fluid that seemed to have the consistency of egg whites. Hiccup asks, "What is it?"

Toothless replies, "Just drink it, it should help you." Knowing how determined he is to get bigger, Hiccup figured he had nothing left to lose, so he tilts the bottle towards his mouth and takes a big gulp of the fluid, finding the taste to be a bit salty but not much else. Toothless comments, "There ya go, champ. Don't worry, everything in there is meant to help you. Some steroids, growth hormone…" He coughs in attempt to cover up the last thing. "Dragon cum."

Hiccup swallows a bit before asking, "What was that?"

Toothless replies, "Uh, Dracunium. You know, to help with…development."

Hiccup had never heard of Dracunium, but figured Toothless knew what he was talking about, so he takes one last sip and hands the bottle back to Toothless. Toothless turns around to put the bottle back into his locker before saying, "Ok, now, you shouldn't expect anything to change overnight, after all a city isn't built in a day, am I right?"

However, right as Toothless was talking, Hiccup began to feel a stir in his groin, and not a stir that he's used to feeling, more like his lower area was heating up by the second making him start to pant. Seconds later, the bulge in his brown shorts began to expand, making the shorts feel tighter and tighter and Hiccup feels his package inflating.

Hiccup didn't know what to do as he wasn't sure if this was because of the fluid he just drank or something else entirely, but what he did know was, moments later, his shorts rip into shreds as his newly sized cock and balls burst out from having grown so much.

Now staring at the human was a cock that was so long and heavy that it flopped down onto the floor in front of him along with a set of balls that felt like they weighed 30 pounds each, quite a lot for Hiccup's inadequate legs. Hiccup's startled look and audible gasp must have been a dead giveaway as Toothless turns around and sees the giant package in front of him and states, "Oh my…did not see that coming."

Hiccup attempts to lift his new giant cock, but finds it to be so heavy that it could barely nudge. "What the ever living crap? H-how can I even move like this?" That's when Hiccup began to feel the same amount of heat build up in his left arm, followed by said arm growing almost twice as long and inflating with muscle that must have weighed as much as Hiccup does.

What's more is that his arm began to get covered by black scales that started at his fingertips and worked their way down to his forearms and upper arms.

Toothless crosses his own beefy arms and stares in amusement saying, "Well, I'm glad I have a front row seat to this!"

Hiccup states, "This isn't funny! I…oh!" Just then, his cock begins to grow even more, and it seems that the heat of the sudden growth was getting to Hiccup as it began to harden to the point where it extended over his head.

His legs seemed to wish to accommodate his new package as they, too, began to double in length and inflate with muscle to the point where Hiccup found himself able to stand, despite his new bedroom sized cock and massive nuts.

Toothless lets out a whistle. "Hot dam! I knew you were attractive, but this is something else entirely!"

Hiccup gives Toothless a glare before holding up his right arm, which was still as pencil thin as his normal self. "Well, what about this, huh?" Right on cue, his right arm expanded and inflated with as much muscle as the left, and his arms and legs were being covered in the same black scales that made their way up his limbs and to his torso in minutes.

His shoulder blades sprout 2 nubs that quickly enlongate and grow into a set of wings while the top of his rear grows another nub that turns into a finned tail.

Speaking of his torso, the white tank top he was wearing gets ripped to shreds as well as his chest bulks up with pectoral muscles that were twice the size of Hiccup's head, a 6 pack that Hiccup could probably hold a boulder on, and his face shifted and changed a bit, his auburn hair receding while his lips expand, and his face extends out to form a muzzle while his ears become pointy and the sides of his head grow 6 nubs.

Once everything was complete, and Hiccup felt the heat of the transformation fade, Hiccup opens up his eyes and looks at a mirror mounted on the locker room wall, looking at a 14 foot tall, beefcake hunk of a black dragon like the one he's been working with for the past month, except with a cock that, in its currently hard state, reached past his head.

Hiccup was somewhat thrown off as a set of beefy hands grab onto his shoulders as Toothless states, "By god, the fluid worked! You're a fucking tank now! How does it feel?"

Hiccup gives his new giant biceps a flex, finding how firm and packed with muscle they truly were, as he states, "Honestly…it feels amazing! I've never felt anything like this! I think I'm now just as big as you!"

Toothless nods to that. "Maybe even bigger! At least, you are in one area." He gestures to the tower of a dragon cock that was sprouting from Hiccup's legs. "Here, let me show you." Toothless then drops his red jockstrap, making his own giant, hard cock spring to life. Toothless comments, "See? I only get up to about 4 feet when hard, I think you're double or even triple of that at least!"

Hiccup looks between the 4 foot pole of dragon meat next to him then to the 10 foot pole looming over his head to confirm just that. How he was maintaining such an erection without passing out from blood loss, he had no clue, but he also couldn't really complain as it felt really good to be so big and powerful, and maybe this is how Toothless feels all the time.

Toothless reaches an arm around Hiccup's 6 foot wide shoulders, snapping Hiccup out of his thoughts before Hiccup asks, "Man, what exactly do you do with a dick this big?"

Toothless smirks to the question. "Well…I can think of one thing…" In a bold move, he brings a hand up to the back of Hiccup's neck and pulls him in, bringing their muzzles together as they lock lips in a deep and passionate kiss.

Hiccup was initially shocked that he was now experiencing the fishy taste of dragon lips, he was going through a wide range of mixed emotions from surprised to happy to lustful. His heart was pounding so hard that you could almost see it through his massive pecs and his giant cock was throbbing even more than before.

A second later, Toothless pulls away from the kiss and smiles wide at Hiccup. "So…how do you feel now?"

Hiccup blinks a few times as he processes what just happened. "Wow…wow…I…I had…"

Toothless puts a finger up to Hiccup's lips and says, "Shh shh, I think this guy here says all that I need to hear." He gives the mid-section of Hiccup's cock a firm squeeze, sending a jolt of pleasure up his spine.

Hiccup couldn't believe it, the dragon he had been drooling over for the past month was now standing next to him in a locker room, bare-ass naked, had just kissed him and was now grabbing his giant cock. Hiccup couldn't help but ask, "Is this some sort of bonus deal I get for training with you?"

Toothless lets out a chuckle. "You're the only one of my clients I have yet to fuck. Originally, I was pretty hesitant about it considering your tiny human size, but looking at you now, I think you can handle much more than you ever could. That is, if you want."

And there it was, confirmation of what Hiccup had been so afraid to ask. Toothless HAS wanted to have sex with him, it's just the size difference lead to many questions about it. Hiccup rubs his upper arm saying, "I mean…"

Toothless holds Hiccup closer and says, "Look, Hiccup, you think I haven't noticed the way you've been keeping your eyes on me this past month? I get that sort of thing all the time, from just about anyone I meet, girls and guys alike, so I know this is what you wanted. Besides, I'm sure you noticed how whenever you do bench stuff I tend to keep my bulge pressed against your head." Hiccup definitely noticed that, especially during the last set of this day's workout.

Hearing that Toothless genuinely wants to do this with him made Hiccup feel like he has a thousand butterflies fluttering around in his stomach. His face grows a bright blue blush as he comments, "Well…can't really go out in public with an erection like this."

Toothless nods to that. "That's the spirit. Alright, first things first, I'd like to see how you are down here." He snakes his arm down to Hiccup's head sized ass cheeks, in the center of which lies his black donut of a pucker, which, even in its clenched state, could easily swallow Hiccup's former head.

Toothless puts his fingers together and pushes them inside said donut, making the squishy walls of Hiccup's anus expand and contract around the digits, sending shivers up Hiccup's spine and making him let out a deep groan. "Just relax, I know what I'm doing." Toothless reassures.

"Listen, uh, Toothless?" Hiccup asks as Toothless proceeds to push his hand further inside Hiccup's ass, getting the whole black hand inside with little to no effort at all, making Hiccup shut his eyes from the rush of pleasure. "I, uh…"

"You what? Gonna tell me you haven't done this before?" Toothless asks with a raised eyelid.

Hiccup rubs his forearm while replying, "Well…yes." He says as quiet as possible. "But, uh, I do have toys at home, just not nearly as big as-OH GODS!" He cries out as Toothless manages to shove his forearm deep into the depths of Hiccup's ass, making Hiccup squeal like a pig and making his eyes roll up into his skull. "Is…is that your arm?!"

Toothless replies with a big smirk, "Well, just my forearm but yes. I must say, that's quite impressive that you're able to take it! The last guy I had could barely handle two of my fingers! Now then…" he says as he pulls his hand out, finding it to be slick with ass juices, and brings his other hand over to dig his remaining digits inside. "…How about a little stretch test?"

Before Hiccup could even think of a response, Toothless digs his fingers into Hiccup's donut and pulls the walls of the black ring apart, making his anus gape wide enough that Toothless could look inside and see the tube of Hiccup's colon. "DAM! Never seen an anus stretch like this! Yeah, I think this could work for the next step." He says as he stands back up and lines the tip of his 4 foot cock with Hiccup's anus and pushes inside.

Now feeling something very thick entering his ass, Hiccup nearly falls forward if it weren't for the wall and his own giant cock in front of him. His tongue shoots out of his mouth as he loses control of his face as he asks, "Is that it? Is your whole cock inside me?"

Toothless replies with a smirk. "Actually, that's just the tip."

Hiccup's heart skips a beat to the fact as Toothless pushes his cock further and further in Hiccup's ass. Toothless tries his best to go slow, as Hiccup is so inexperienced with this new body, but the warm tightness around his cock was simply pulling him in with each thrust.

It wasn't too long before Toothless found himself pushing far into the depths of Hiccup's insides and it wasn't much longer than that before the center of Hiccup's black, beefy chest began to bulge out from the tip of Toothless's cock.

Looking over Hiccup's shoulder and seeing the pectoral bulge Toothless was making, he couldn't help but comment, "Oh, dam, you even got my stretchy torso."

Looking down and seeing the tip of a 4 foot cock poking through his giant chest, Hiccup didn't know whether to be concerned, scared, delighted or all of the above. "How in the…?"

Toothless gives Hiccup a pat on the shoulder saying, "I wouldn't worry too much about it, just let me do the work."

Toothless then wraps his muscular arms up through Hiccup's armpits and wraps them around his chest as Toothless begins to pull his hips back and forth in a gentle but increasing motion, feeling the newly created Night Fury's insides heat up with each thrust of his giant cock. "Though, I will say…" Toothless says as he starts pumping. "With how tight you are, I don't think I'll last much longer…" Hiccup's eyes roll back in anticipation.

Each time Toothless thrusts forward, his cantaloupe sized balls would swing forward and gently smack Hiccup's hind legs and the backside of his own giant set of balls, making his giant rod of dragon meat twitch and throb and send waves of pleasure up his whole body.

Hiccup really didn't know what to do with his over-the-head long cock at this point, especially since there's a smaller but also giant cock working its way through his ass. All he could think to do was wrap his beefy arms around said cock and hold on as Toothless thrusts into him harder and harder.

True to his word, it didn't take long before Toothless thrusts one last time and begins to fire a hot, creamy load of dragon seed at such a force that his cock ended up shooting out of Hiccup's ass with just a few shots, his cock then dumps cum all over Hiccup's ass, lower back, legs, and puddles up on the floor below, looking like someone just dumped a pint container of heavy cream all over the floor.

After his orgasm subsides, Toothless says through many pants, "Thanks…for that…Hiccup."

Hiccup, also panting like he just ran a marathon, replies, "Yeah…no problem." However, it seemed that it wasn't quite the end there, as only seconds after getting his ass filled by Toothless does Hiccup's cock begin to heat up to a near boiling temperature as it expands by another foot or two in length and his balls increase to the size of watermelons, audibly churning and sloshing from how packed with Night Fury seed they were.

Regaining his composure and looking up, Hiccup saw that his cock was now only a few feet below the locker room's ceiling as he comments, "Did…did it just get BIGGER?"

Toothless met Hiccup's gaze as he stares in awe over the even bigger schlong that Hiccup had grown and realizing at that point that it was simply too much. He decides, "Ok, we gotta get you to cum and soon." He then turns around and bends down before gripping his huge, black ass cheeks and spreading them apart while lifting his tail high up, showing the massive donut that sits between the musky cheeks, as he says, "Here, put it in here!"

Hiccup really didn't see any other option here, so he lowers his cock and rests the melon sized tip on the top of Toothless's rear, putting him at almost 2 whole humans length away from the born Night Fury and saying, "Ok…you sure you can handle this?"

Toothless nods. "I've handled a lot of big guys, Hiccup…ok, maybe not nearly THIS big, but I think I can manage."

That was enough for Hiccup to proceed as he begins to push his monstrous cock tip inside Toothless's ass, making the ring of his puffy anus expand and take the tip with ease. As soon as Hiccup felt the tight walls of Toothless's rectum around his giant, ultra sensitive cock tip, he nearly came then and there as the pressure was that good.

"Holy fuck…I don't think I'll last 5 minutes." Hiccup comments with a shocked look as he couldn't believe how good this felt.

Toothless nods. "The sooner you cum, the better...although that does feel really intense!" He shuts his eyes and clenches his teeth as he gets ready for the ride of his life.

Hiccup nods to that and proceeds to push his giant dragon rod inside Toothless's ass, feeling the tight walls of his insides wrap around his cock more and more. Due to the sheer size of Hiccup's cock, it wasn't long at all before one could see a considerably sized bulge popping out of Toothless's abdomen.

Toothless could do nothing more than to grip his knees and let Hiccup do his thing. His heart was racing in tune with Hiccup's, something he could feel through the monstrous cock in him, he was at a near loss of breath and the pleasure in his ass was almost too much to handle.

It didn't take long at all before Hiccup thrusts one last time before his giant balls tense up and his cock begins to dump, not just shoot, dump cum into Toothless's ass, but unlike before, Hiccup's cock tip was so wide that it was blocking any sort of flow out of his ass, so all that cum just ended up pilling up in Toothless's ass and causing his firm 6 pack to blow up like a balloon, giving him a significantly large belly.

After a few minutes of dumping his giant balls, Hiccup's cock found that there was no room left in Toothless's abdomen, so its fat tip ended up shooting out of his ass with an audible pop, spraying one last shot of Hiccup's dragon spunk that coated Toothless's anus like a glazed donut.

After taking a moment to recover, Toothless looks down and was in complete shock over what he saw. What was once a beautiful 6-pack was now a giant cum belly that looked like he just swallowed 5 humans whole, not that he WOULD do that sort of thing.

Toothless had to sit down as the sudden added weight of his belly was quite a lot as he gives his belly a poke, finding it to be really squishy and gurgling from all the cum in it. His fat cock and balls getting slightly crushed from its weight, crushed in a way that Toothless ended up shooting another small wad of cum onto the puddle he had already made. He then comments as he pokes his belly, "Ok…I will admit that I didn't know what I was expecting, but certainly not this."

Hiccup rubs the back of his black neck. "Yeah, sorry about that, didn't know how to control myself there."

Toothless shakes his head. "No need to apologize, my sexy friend. You're not used to that new body of yours, and you just needed to let go. I'll happily sacrifice my abs for you again any day. So, how do you feel?"

Hiccup replies, "Really good, actually. Although…I'm starting to feel….weird again…"

He says this as, once again, he feels his whole body heat up like he was on fire, which Hiccup initially thought meant he was about to grow bigger, but that's when the opposite begins to happen.

His wings and tail shrink and retract back into his body, his arms, legs and torso deflate in mass as his black scales retreat back into his skin, his face shifts to a more human face and his hair grows back, and while his cock and balls aren't nearly as big as they were minutes ago, they do seem to hold onto a rather large size, giving Hiccup an 11 inch long cock with a set of peach sized balls.

After feeling the rush of the un-transformation, Hiccup looks in the mirror again and sees his usual human form before commenting, "Whoa, I'm…me again."

Toothless comments as he finds his footing, despite his gigantic belly, and comments, "Yeah, you are. Guess now we have a better understanding of how that fluid works."

Hiccup had to admit that he was a bit disappointed to be back in his human body, but at the same time he was somewhat glad he didn't have the burden of figuring out how to get a 12 foot cock out the door, especially since his clothes were already ripped to shreds.

Realizing just how good it felt to be so huge, Hiccup looks up to Toothless and asks, "So…same time in 2 days?"

Toothless lets out a grin as he gives Hiccup's slim shoulders a gentle pat. "I'll do you one better, why don't you swing by my place and we can try out that fluid again?"

Hiccup was absolutely delighted by the offer, but that's when a voice comes up from behind him. "Oh my goodness, congratulations!" Hiccup turns around to see a red, slim male dragon walking up behind him. Before Hiccup could even ask who this dragon is, he puts his hand on Toothless's beach ball of a belly. "So, who's the daddy?"

Realizing exactly what is going on here, Toothless puts a hand behind his neck and puts on a wide, close eyed smile and comments, "Well…it's actually a funny story…" Hiccup lets out a few chuckles himself as he tries to figure out how to explain this.