Big ADHD Energy

First of all yes I'm aware that pretty much every decision made about their design was with consideration of the effect it would make on human audiences but hear me out

Night furies are most iconically known as dive-bombers. They are built for speed, high maneuverability, night-time camouflage and for striking targets from above. If we remove human settlements out of the equation (which would not have existed long enough to actually influence night fury evolution, come on), what does that leave us with?

They aren't built for catching fish for sure, they aren't very hydrodynamic and their head is round, wide, and their teeth are dull. Honestly, the monstrous nightmare is much better suited for catching fish, with its long neck, almost pelican-like jaw and rhamphorhynchus teeth

Compare to

Yeah the jaws look kinda like a porpoise of some sort but for that the whole body would have to be a lot more aquatic imo. The light fury looks a lot closer to an aquatic diver, it has a sleeker body, rounded fins instead of spikes, and a long neck.

I don't really see them hunting land animals either, they just don't look like they're adapted for that minus the resemblance with large felines and even then, they're too large to effectively hunt in forests.

The one thing I can kinda imagine them hunting is large mainland megafauna, but we're working with a setting that takes place pretty much exclusively on islands. And overall, dragons are the only abundant species there with the exception of fish and human-bred sheep and chickens.

In general, night furies have duller teeth, smaller claws and are smaller than most dragons. Disregarding the movies making Toothless weirdly OP, a night fury would be disadvantaged against most dragons in a 1v1 fight and besides, it has four huge weak spots that would highly discourage it from a direct physical fight - the primary and secondary tail fins. One unlucky rip in the membrane and the night fury is fucked.

The night fury however noticeably resembles falcons, given their dive-bombing ability and high maneuverability.

Falcons too have smaller beaks and weaker claws compared to most birds of prey, and for that they compensate by simply picking up speed, balling up their talons and Punching. Really. Hard.

And they use that ability to kill other birds, even much larger ones, by knocking them right from the sky.

Here, the night fury's plasma blast works the same way as a falcon's punch. Dragons are fire-resistant, so what the plasma blast does is really just a densely packed bolt of energy that has the effect of either stunning or outright killing prey by damaging its spine. And what the plasma bolt doesn't do, rapid contact with the ground would finish. And if even that doesn't do it, the night fury's wide jaws and dull teeth are just fine for simply clamping around the unlucky dragon's neck and strangling it, like a lion or a pitbull.

The night-time camouflage allows the night fury to soar for extended periods of time perfectly unnoticed in the night sky, and by the time it strikes, the dragon wouldn't even know what's coming.

Unless

Say the hunting night fury is aware of other dragons sleeping under the trees, as most dragons probably would at night (village raids aside, most dragons seem to be diurnal), so how does the night fury get them in position where it can use its signature attack? Well, there's That Iconic Screech Of Death. Since in the movies it tends to appear not just during dive-bombings but also when charging up a blast, I imagine it's something the night fury is able to control to some degree. So by simply fake-diving in close proximity to sleeping dragons, it can effectively terrify them into leaving their hideout and fly out into the open where it can easily take them out.

I dunno, the possibility of night furies as predators to other dragons just makes so much sense to me, I really don't know what other reasons there would be for them to evolve these particular adaptations.

And one more little headcanon to add to this whole rant - since night furies are significantly smaller and less equipped for dragon vs dragon fights and are primarily speed-based predators, I imagine there is this very likely scenario:

There is one dragon who resembles a hyena, a lil bit