Switching certain infobox and trivia sizes was my doing. For the most part, I believe, my calculations are still in the trivia. However, there are 16 species for which I did specifically either update or replace the official info. I say 'update', because for ~6 species, the sizes listed on the Dragonpedia charts (among other sources), were revealed to actually be the height of the model, instead of the length. Richard once said they never measured height, but it turned out he was wrong.
As for how this was 'revealed,' well, in the summer of 2021, an anonymous user had —by all indications— leaked and uploaded to a 3D modeling website 18 of DreamWorks' in-house models.
Eighteen models, but 2 of them have 2 versions (adult&baby Gronckle, and 2 Bewilderbeasts). The models appear to have been somewhat retopologized to have a lower poly count, but overall match far too closely with models in test- and development footage by DreamWorks to be fan-created. They also have an overwhelming amount of detail, as seen with Toothless's prosthetic tail here:
Sizes I added for the Terrible Terror, Gronckle, Scuttleclaw, Skrill, Hotburple, Night Fury, Nadder, Rubmlehorn, Whispering Death, Nightmare, Zippleback, Seashocker, Stormcutter, Thunderdrum, Timberjack and Bewilderbeast are taken from these leaked models.
Let's also account that, somehow, by magical means, Toothless' bloodline took on the Alpha role for 1000 years? The main franchise, a you also pointed out, establishes that the tilte is earned through combat. Not passed on willingly, or inherited from parent to child. The next Alpha after Toothless was whoever defeated him. Or, if none, the strongest one currently residing in the realms. Which let's admit, wouldn't be his kids, even if they did some light hearted, in-family combat.
Otherwise, yes, Jormungandr should have taken the Alpha's title as he killed the Elder.
Not gone, just private. It's available through direct links: https://www.reddit.com/r/httyd/comments/xxgssc/audrie_greywind_unpacking_the_unreleased_httyd/
Not a fan of Audrie at all either, but that interview is pretty much the only source of information about the Fire Tides. So it better remain available in some capacity.
Just for the fun of it, I really hope the Dragon Manual is destroyed as well. These things survived 1000 years in a place full of giant, fire-breathing lizards, but when they fall in the hands of some zoomer kid, they are ruined within an hour. Entertaining, to be honest.
Oh, nice. The Nine Realms had successfully destroyed two of the most recognizable relics of the main franchise. What a distasteful offense.
It seems they were made private. For some reason.
"Yes Jormungandr is smaller in terms of width, but he's the longest dragon we've seen on screen. I'm ending this argument with this: Because the developers said he is"
Surely I must have missed this. Care to provide the tweet where Tellegen confirms this? If there's one at all.
Based on what we have truly seen on screen, Jormungandr is nowhere near 24,900 miles long. Not at all.
We don't know whether the Submaripper was a Titan or not. It is the only specimen seen in the franchise, and it is not specified to be any particular stage of growth. The Titan Shellfire was something like 2x bigger than the Submaripper.
The Nine Realms is also a low-budget show, I wouldn't really base any info on their portrayal of things. They clearly have limitations on how big they can make their characters, and that scale kinda tops off with the Sky Torcher and Jormungandr. Pretty much none of their "gigantic" species have been particularly large, most main franchise dragons were similar in size.
So that Shellfire might either be the actual size of a Broad wing, or it might just be as big as they were able to go with their budget.
And I meant, that we have seen a couple of pages from an early draft of HTTYD2's script, and it had Drago's Bewilderbeast controlling Red Deaths (plural) to destroy some village, somewhere.
"is immune against the Bewilderbeast-hypnosis."
Not known, but an early draft of HTTYD2 opposes this.
"The Red Death seems to be the natural predetor of the Bewilderbeast."
What's this based on?
"And only a Titan-Shellfire is a little bit larger than a Submaripper and was nevertheless defeated by him."
We don't really know if the Submaripper wasn't also a Titan Wing.
"A normal adult Shellfire has the half of the size of a Submaripper"
There's no universal multiplier for the size change between Titans and Broad Wings, not one that is applicable to all species. Titan Skrills are 4x larger than a Broad wing Skrill, while a Titan Nightmare is about 2x bigger than a regular one. Titan Eruptodons are barely bigger than their younger counterparts. It's not known how big younger Shellfire might be.
"He is at least twice of the size of the Titan-Shellfire."
Both are about the same size actually, the Bewilderbeast is 2 Shellfires long.
"In Season 8 the Jormungandr has the size of the Screaming Death."
Now if you would kindly take a look at the picture above...
Just to give a bit of perspective... Here's a line-up of the Bewilderbeast, Red Death, Death Song, Fault Ripper, Night Fury, and Thunder. We have seen that the Sky Torcher's size is comparable to the Fault Ripper's, and later, that the Jormungandr isn't much bigger than the Sky Torcher. Make your own conclusions.
They don't even use real letters in their own language, just some idk, galactic federation glyph text to fill the space. It's too much for a budget like this show's to expect anything better.
There seems to be a misconception people always fall into. Race to the Edge doesn't end a year before HTTYD2, it BEGINS at that time. Dragon Eye of the Beholder, season 1 episode 1, is set 1.5 years before the movie. This was established by the showrunners themselves. Then, we have verbal confirmation from the characters, that exactly 1 year passed between season 1 episode 7, and season 5 episode 7. That still leaves a whole season and a half, and only half a year at most, left until HTTYD2 comes around on the timeline. The series is all but confirmed to conclude during the very same summer in which the movie takes place.
Also, these are WhispertheWolfie's theories from DeviantArt... so please give them credit.
DracoBaltoy II, my point is not invalid. At no point in the franchise does Toothless control dragons' minds. He can give a command that dragons will follow out of respect for him as "alpha", but mind control is an ability unique to the Bewilderbeast.
About your other questions, the series does not elaborate on how dragons recognize the alpha, it might be a pheromonal thing.
Primebee28, Phantom controls the Purple Death and tells it to go back to sleep. Even if we discard the Titan comics, their hypnosis ability still remains, having originated in Book of Dragons (2011).
Toothless has no control abilities. Bewilderbeasts do, and Changewings can hypnotize, but that's all.
I always assumed she was someone like Lars #2, a random name-drop, nothing more.
The game files call it Crystal Whip for what it's worth, I don't recall the gameplay itself.
However, the screenshot from the game should confirm it is indeed one word.
I believe there would've been less name-calling if the writers didn't choose to have Leonard act like a child and start calling himself a ridiculous nickname. He doesn't even have a buzzsaw, he has an axe! Heck, even his logo is a hand saw, not a buzzsaw...
Titan Uprising is barely a canon source. Dragonroot agitates dragons, as seen in Riders of Berk and RTTE, it does not enslave them. If anything, Eir's Grimora-Dragonroot potion is the only thing that would work, but the Dragonroot company most likely didn't have that.
This was a passageway to the Dark Realm, located inside the Crystal Realm.