Hey everyone! Here is my one-shot titled "Mismatched Sizes, Equal Brothers", you're probably curious about the title and what it means but don't worry, all of it will make sense in a little bit. I wrote this fanfic after coming up with the idea while brainstorming for my OTHER fanfic titled Finding Home, and it didn't seem like something I could turn into a multi-chapter story so I just wrote a simple quick one-shot. The only characters in this are Hiccup, Toothless, and a few Monstrous Nightmares. And this is set post-HTTYD1 by about a few weeks (6-8 if you want a number), so yeah, let's get right into this:

ALSO: NOTE: I have seen HTTYD2 and know Toothless' age in canon for the movies, if your wondering why I'm stating this, you'll know why later. But anyways, back to:

Mismatched Sizes, Equal Brothers


Hiccup knew something was wrong with Toothless, he just knew.

It had all started around a few weeks after the defeat of the Red Death, and the start of peace between Berk and the Dragons. Toothless and Hiccup had been helping get some Vikings and Dragons used to each other when Toothless had lost balance and hit the ground from around twenty feet in the air.

They were both alright, and Hiccup had thought that maybe he had moved the pedal in some wrong way by accident and cause the mishap but the true reason was weirder and...strange.

Toothless' prosthetic tail fin was not the same size as the real still intact flesh one beside it, and Hiccup was shocked and annoyed somewhat, mostly at himself.

Hiccup was CERTAIN he had double-checked and quad-double checked the measurements of Toothless' tail fin before constructing the prosthetic, but Hiccup just chalked it up to Gobber rebuilding the fin a bit smaller than before.

Now if it stopped their then Hiccup probably wouldn't be pondering what he was right now, but it didn't stop. In fact, the number of incidents that include the words Toothless in them increased over the next few weeks.

The next week, Toothless had begun clawing at his saddle harness with moans and groans, trying to get the thing off or so Hiccup thought.

Hiccup chalked that up to Toothless' gain weight and a bit of fatness, as the Night Fury had been eating more and more lately, so much that it leads to NEXT weeks problem.

The problem happened early one more when Toothless broke into the storehouse and helped himself to some fish, of course, the dragon was only so big but he did manage to scarf down enough that his stomach was practically bulging.

And then finally came last weeks problem, and at this point, Hiccup was getting annoyed and frustrated. He cared about Toothless a lot, more than anyone else in the village (Astrid excluded, she and Toothless were on equal levels of love from Hiccup), but the dragon was starting to get on his nerves.

This time, Toothless had shed some scales around his stomach and legs, and Hiccup just chalked it up to the PREVIOUS incident, but when Toothless had grown in double the number of scales he had before and Hiccup tried touching them, Toothless was whimper and back away.

That's when Hiccup's frustration vanished as dread filled the Viking's entire body, something was obviously wrong with Toothless and he had been completely oblivious this entire time.

So, Hiccup brainstormed and thought for hours at a time trying to deduce the problem and fix it before Toothless' health or even life were put on the line.

Hiccup quickly narrowed down that it wasn't any normal dragon diseases, even though they're knowledge of Dragon diseases was pretty limited (Up until the peace) they still had a rough understanding of them.

But it wasn't any normal one, and whenever he went to Gothi she just dismissed it with a smile, not telling him what she knew. And that drove Hiccup insane to no end that someone was keeping secrets about his best friend from him.

Hiccup would try asking Toothless because he knew the dragon understood Norse, but he didn't want to send the Night Fury into a panic if he found out that he was sick or worse, dying.

Hiccup crossed his fingers and prayed to Thor and Odin that it wasn't the latter, he couldn't lose Toothless after everything they've gone through in the past few months.

But he was still without an answer, so, Hiccup sighed and went to sit by the main fields were Dragons roamed and talked to each other in a language Hiccup was still having a hard time deciphering.

And that leads up to the present, were Hiccup was sitting on a huge stone watching as two fully grown Monstrous Nightmare's nudged a baby Nightmare out from the nest so the baby could see the world.

Hiccup watched as the baby dragon examined his surroundings, fascinated and curious about the field, the grass beneath his feet, the blue sky, and even the rock that Hiccup was sitting on.

"Huh, sorta reminds me of Toothless..." Hiccup remarked with a smirk, chuckling a bit as he did.

He remembered when Toothless was first brought into Forge, the dragon would not stop examining and trying to nudge or lick anything and everything in the building.

Hiccup quickly shook his head and stared at the hatchling again as it wandered back into his nest, his parents waiting for him.

That's when Hiccup noticed that the baby also had double the amount of scales normal baby Nightmare's had, and they were around his legs and belly just like Toothless.

Hiccup hummed and jumped off his rock, quickly walking over to the nest which was hidden in the side of a hill, he peered inside and saw the hatchling gorging himself on tons and tons of fish.

"Is just me or is this hatchling repeating Toothless? What is this little guy, a follower of the Tribe of Toothless, population 2" Hiccup joked to himself but then went into his famous thinking mode.

The hatchling and Toothless' actions were similar, if not almost the same. And Toothless' tail fin had got bigger than the prosthetic...

It all clicked in Hiccup's mind, and at that moment the Viking want to cheer from the rooftops.

He knew what was wrong with Toothless! It actually wasn't anything serious, the dragon was just growing and all was perfectly normal.

But one thing still nagged at Hiccup, and he couldn't help but talk to himself about the thing that nagged him.

"I don't get it, most dragons stop growing majorly by the time they reach adolescence, and this kind of behavior really only happens in hatchlings and sometimes early fledglings, so how could Toothless be doing it if he's an adult...unless..." Hiccup mumbled to himself as he started walking from the field and back towards the village.

"Unless...Toothless is still a hatchling" Hiccup nearly whispered as it finally clicked and everything made sense, all the puzzle pieces came together and all of Toothless' strange actions finally made sense.

Then, Hiccup paled as he thought of how big Toothless was going to get. If the dragon really was still a hatchling, then he would eventually grow up into an adult over the course of a few years...

But the one question in Hiccup's mind was that of how BIG the black dragon was gonna get in the next few years, and the young Viking seemed to phase out as a scenario came to mind.

In this scenario, Toothless was bigger than Berk, so big in fact that the Red Death looked like a Terrible Terror compared to him.

Toothless yapped and barked, pointing with a paw at a basket full of cod. The imaginary Hiccup stepped forward and grabbed the cod before throwing it into Toothless' massive maw, comparable to a thousand Viking longships in length.

Toothless nuzzled him purring, and Hiccup had the air literally punch out of his lungs by the massive dragon. The nuzzling continued but Hiccup found it odd that even though he was flat on the ground, he felt the nuzzling on his back...

Hiccup snapped out of his fantasies as he realized Toothless, the real medium-sized black dragon, was nuzzling him worryingly.

"Toothless, are...are you a hatchling?" Hiccup asked hesitantly, dreading the answer.

If it was yes, Hiccup would be happy that Toothless was alright but guilt-ridden that he stole free flight from a hatchling as well as dreading how big Toothless might get.

If he said no, Hiccup would worry about what was wrong with dragon and would not be as guilt-ridden as if it was yes, but he would still feel guilty anyways no matter what.

Toothless' eyes widened, the dragon being shocked and caught off-guard by the question. Toothless slowly be hesitantly nodded, worried about Hiccup's reaction.

Hiccup imminently jumped up and flung himself at Toothless, hugging the dragon's head close to his chest.

"I'm so so sorry...so...so sorry...I regret it, I'll always regret it" Hiccup whispered as tears fell from his eyes, splashing onto Toothless' onyx-colored scales.

Toothless keened and crooned as if asking Hiccup what he meant by regret, and the Viking choaked down his sobs before gesturing to Toothless' tail.

"I regret maiming you, I regret stripping you of your free flight...I'm sorry bud, I wish...I wish I could go back in time and undo that, restore what I took from you..." Hiccup whispered weakly, gesturing again to the tail, which only had one fin.

Toothless whined and nuzzled Hiccup's chest, trying to tell the boy all was forgiven. But Hiccup couldn't accept that, the simple fact that he had stripped a hatchling of free flight would forever haunt Hiccup for the rest of his life.

"I'm sorry, so...so sorry" Hiccup whispered weakly and his eyes flickered over to the tail, the one fin making the dragon's tail slightly lop-sided.

"I did this..." Hiccup stated weakly, his heart skipping a beat and his breath stopping for one second before restarting.

Eventually, Hiccup took in a deep breath and let go of Toothless, the dragon nuzzling Hiccup and licking the Viking's face to show that he was forgiven.

Hiccup knew Toothless forgave him now, but what about in a year? Five years? Ten years? What about long after that?

The simple fact that Toothless could possible grow to hate him in the future hurt more than any weapon ever could.

Hiccup held hope in his heart that maybe he was just being paranoid and that Toothless would never hate him, but the young Viking still couldn't help but worry.

Hiccup knew people changed as they grew and since Toothless was only a hatchling that meant the dragon still had a LOT of growing to do, and the possibility that Toothless might one day hate him was there but yet not at the same time.

Hiccup decided at that moment that he would try everything in his power to make up for every wrong thing he's done to the dragon and that he would start RIGHT NOW and would not stop.

"T-the saddle's probably a bit too small for you know, bud? Do you want me to get it off?" Hiccup asked as if the past few minutes hadn't happened, and Toothless nodded slightly with a croon, confused as to why Hiccup had stopped crying but deciding to not bother the boy about it.

Hiccup quickly undid all the straps and buckles that kept the thin piece of leather on Toothless' back, and once the saddle was off Hiccup threw it aside for later work.

That's when Hiccup noticed how Toothless' entire body seemed just that tiny bit bigger, new scales covering the dragon's entire body to replace the old ones that were too small.

Toothless started doing the dragon form of stretching, going from the position of a cat when it yawned to the position of a Viking after a long day and a ton of mead.

Hiccup would have laughed at any other time, any other day. But Toothless was probably sore from being stuck in a small and very tight saddle for days while Hiccup took forever to figure out the truth.

"Bud, want me to help?" Hiccup asked softly and Toothless purred before lying down in front of the Viking.

Hiccup quickly started rubbing the dragon's sides and back, and eventually Toothless rolled over to let the young boy rub his stomach and chest, which ached badly.

"Alright, done. I would continue rubbing but I don't really want to spoil you, you useless reptile" Hiccup remarked with a smirk, and Toothless rolled his eyes.

Hiccup wondered as well how smart Toothless would be as an adult, Toothless was already regarded as the smartest dragon on Berk (Enough even outsmart Hiccup sometimes) and he was only a hatchling!

Then the thought of how big Toothless was gonna get came back, and Hiccup closed his eyes while crossing his fingers.

"Thor, Odin, please do not let Toothless get bigger then a Titan Wing Monstrous Nightmare" Hiccup repeated over and over again.

Toothless snorted with a roll of his eyes but was even himself a little scared at the prospect of becoming huge, then he would have to be even more careful with Hiccup as to not hurt him and he could no longer cuddle or nuzzle the boy like he normally did.

Eventually, Hiccup opened his eyes and smiled at Toothless, scratching the dragon under the chin.

"Come on bud, let's go get you some dinner, and expect it to be able to fill the bottomless pit of what you call a stomach" Hiccup joked and they both walked off towards Berk.

Now, Hiccup wasn't as terrified as he had been before at Toothless possibly becoming as big as a Red Death, no...he was more terrified at the prospect of explaining all this to his father...


(Now, from here on out, the fanfic actually has a flashforward to five years in the future (Around HTTYD2 time for reference), but I decided to write TWO endings instead of one. Each has Toothless at different sizes but mostly the same content. Each ending is canon but not, it's up to you to decide which ending you think is canon in YOUR opinion)

(ENDING 1: Medium Sized Toothless)

It turns out that Toothless actually didn't grow very much over the next five years, only growing about a foot or two in height before reaching the fledgling stage and mysteriously no longer growing.

Hiccup chalked it up to a theory that Night Fury's stopped growing once they reached the fledgling stage of aging, but all of that was still a theory.

Since Toothless wasn't the equivalent to a Viking long-ship given legs, a tail, and a built-in flamethrower like Hiccup had feared, that meant their lives could go on as mostly normal.

Hiccup looked out for the dragon a bit more than he had before, helping and making sure the dragon was happy and joyous at every moment.

Hiccup sat down in a chair, black leather armor on him and Inferno lying on a table nearby. Toothless rested his head on Hiccup's lap, the Viking scratching absentmindedly at the dragon's neck.

"You know bud, no matter how big you could have gotten, I would still care about you all the same" Hiccup whispered with a smile, and Toothless smirked while bringing his one tail fin up to Hiccup's one leg.

Hiccup's fear of Toothless hating him had died off after a few months since it first began, Toothless had truly forgiven him and Hiccup would allow himself to be forgiven as long as it made the dragon happy.

After all, they were closer than any other Dragon and Viking in the world, they were practically brothers.


(ENDING 2: Huge Toothless)

It turns out that Hiccup's estimation of Toothless getting as big as the Red Death was very overestimating.

Toothless grew and grew, and then grew some more. But the dragon stopped growing once he was around twice the size of Hookfang, but the dragon had only reached the fledgling stage.

Hiccup chalked it up to a theory that Night Fury's stopped growing once they reached the fledgling stage of aging instead of adolescent like other dragons, but all of that was still a theory.

Their lives went on mostly normal, but a few changes had to be made in order for them to live with the now fully grown Toothless.

Such as, the dragon now ate nearly quad-double the amount of fish he used to eat only about five years ago when Hiccup first discovered that he was a fledgling.

Hiccup had wanted to expand the Haddock house so Toothless could sleep and fit inside, but the dragon was just too big now to get through the front door or even the window in Hiccup's bedroom.

So, Hiccup had the village build a new section of the Haddock house that Toothless could fit in and move around comfortably.

Hiccup had also moved his bedroom down to the same room as Toothless, he was so used to sleeping in the same room as the dragon that he didn't want that to change.

Hiccup looked out for the dragon a bit more than he had before even though Toothless was stronger than ever before, he still helped out and made sure the dragon was happy and joyous at every moment.

Hiccup laid his back against Toothless' chest and belly, the huge dragon purred and offering his head for support.

Hiccup laid down on Toothless' head, fitting perfectly on top of it while he scratched the dragon's scales, causing Toothless to purr.

"You know bud, no matter how big you've gotten or could get, I would still care about you all the same" Hiccup whispered with a smile, and Toothless smirked while bringing his one tail fin up to Hiccup's one leg, the tail fin acting almost like a blanket to the young boy.

Hiccup's fear of Toothless hating him had died off after a few months since it first began, Toothless had truly forgiven him and Hiccup would allow himself to be forgiven as long as it made the dragon happy.

After all, they were closer than any other Dragon and Viking in the world, they were practically brothers.


Alright! That is it for "Mismatched Sizes, Equal Brothers", if you guys want I may or may not turn this into a two-chapter one-shot (What's that even called anyways?) set between the time jump where we can get some pretty hilarious scenes from Hiccup and Toothless, we might even get to see Stoick and Astrid and the others if I get around to writing it (But don't count me on it, unless people are requesting it then I'm just gonna leave this as a one-shot).

So yeah, please leave a review and tell me your thoughts about this short fanfic, this is JustANormalHTTYDFan, over and out.