!! First Film
* The falling scene, especially once they pass the peak of the mountain.
* [[spoiler: The Red Death's [[JumpScare introduction]]. You HAD to feel seriously sorry for that poor unfortunate Gronckle.]]
** Lets not forget about the unlucky Hideous Zippleback that, too, got dragged down and eaten by the beast afterwards.
* [[spoiler: The Red Death, a dragon the size of a very large hill, taking flight and ascending into the sky after Toothless and Hiccup. Having it emerge from the earth is terrifying enough, but seeing something that looks like the unholy spawn of Fenrir and Jörmungandr take to the air and disappear into the clouds left one awestruck. That's the point where the Vikings probably thought that [[NorseMythology Ragnarok has started and the world was about to break.]]]]
** [[spoiler: Not to mention seeing it breathe fire when it can't keep track of where Toothless is flying. When most of the other dragons have been shooting quick bursts of fire, watching the Green Death freak out and unleash this continuous stream of flames through the sky is just terrifying.]]
** [[spoiler: Lets also not forgot the things [[MoreTeethThanTheOsmondFamily teeth]]. While all the dragons in the film have lots of teeth that are proportionately very big, its stand out more thanks to how huge it is and that it has a mouth like a therepod]].
* Also some of the details on the various dragons in the handbook.
-->'''Hiccup:''' Eats its victims... burns its victims... buries its victims, chokes its victims, turns its victims inside-out... Kill on sight.
See [[NightmareFuel/HowToTrainYourDragon2 here]] for the [[DarkerAndEdgier second movie]].