Elder Dragons might be Aliens - Here's why... 

Almost every Elder Dragon: *Uses powerful elemental abilities to overpower its enemies* Nergigante: "The hunter gonna catch these hands"

Also to be noted that elder dragon classification is rly just a way to say "we rly don't know wtf is going on" in-lore. To be noted that 2 out of 3 elder dragons in 1st gen are quadruped.

Dracophage bugs feed on the dragonfell berry. Its the only plant able to naturally produce the dragon element and is quite rare, making dracophage bugs quite rare and in extension making stygian zinogre quite rare.

Nergigante is described as an elder dragon killer , a sort of elder dragon ecosystem regulator that changed shapes over time from old gens , older designs with scales instead of spikes were revealed by the official MH channel during last stream for "hunters choice"

Similar theory elder dragons are from alternate realities biggest evidence is behemoth being classified being an elder dragon even though it’s non-native to the universe

this video is SO PERFECT

I personally view elder dragons to be the extremophiles & dinosaurs of the world, being the most ancient class of monster and come from a completely different lineage of creatures separate from wyvern or insect, they are as separate from other creatures as vertebrates vs invertebrates, and they originate from a time the world was in climatic turmoil, thier ability to have extraordinary abilities may be due to them adapting to these great dying events and where the only animals able to survive these harsh conditions and now use there use thier almost supernatural abilitys to rule the world as its now known, it fits with my view of most elders being half animal half mythical and with a intelligence that matches and even surpasses man, I do think xeno'jiiva/safi'jiiva are aliens tho but for me that's special case, and i do think the black dragons are just straight up mythical apart from alatreon, I'm not sure where I put him on this scale

Underated ,like REALY REALY UNDERATED keep it up

We know due to encyclopedias and official art books that the world pf monster hunter is quite old, as an “advanced ancient civilization” existed long before the guild’s inception. While the lore behind this civilization is quite spotty, we know due to areas in game like the Tower that this civilization existed, and they interacted with elder dragons too. In fact, locations like the Tower were made primarily with elder dragon materials, implying that elder dragons were much more numerous then they are now. There’s supposedly even an in-universe explanation, since there’s multiple references to a “great dragon war” between the civilization and the elder dragons, leading to the death of the great civilization, and the loss of many elder dragons, likely even the extinction of several ancient species of elder dragons that we’ve never seen.

Cool theory! What are your thoughts about ebony odogaron?

I think that the dragon element is a derivative of the bio energy introduced in gen 5, we see safi use pure bioenergy which many have hypothesized to be “pure” dragon element, due to it being weak to any element since if it were dragon element in its purest form any derivative of bioenergy would be enough to tip its internal energy off balance, and this ability to tap directly into bioenergy is what gives elders their command over the elements, which can be seen as derivatives of pure bioenergy, even Nergi’s strength can be seen as an abundance of bio energy cultivated from the proximity to the everstream. This hypothesis is also supported by kulve taroth, and elder dragon which lives its life along the everstream. It seems plausible due to the importance the MHW story put to bioenergy and the everstream, tying it into behavior of all elder dragons, even those in the old world with the elder crossing.

The idea that elders are aliens becuase they have six limbs and that they landed on earth as single called organisms while Wyvern ancestors were single called organisms doesn’t make any sense and are contradictory. There’s nothing stopping terrestrial single called from having 6 limbs, there’s nothing there suggesting no common ancestor if the supposed divergence was so long ago. The idea that Nergigante is an alien because it’s “just too strong” feels like a “play other games” moment, because Bloodbath Diablos would have words for that, lol Additionally elders are sometimes speculated to be the ancestors of modern creatures (Dos and Freedom Unite) and Tigrex (a primitive Wyvern) is said to have limb structure similar to that of elder dragons (Freedom Unite in-game Hunter’s Magazine). You also forgot Ebony Odogaron, who produces dragon element as a result of it consuming large quantities of meat (and not just eating elder dragons, which Deviljho as a species is not confirmed to do by any stretch) as well as Rathalos and Tigrex, who both have dragon element in their bodies (and used to have dragon element attacks prior to third gen, having been removed because of the addition of blights in ‘Monster Hunter Tri’). Dragon element is also found in Vespoid and Hermitaur, as their weapons were some of the only dragon-element options in MH1, and have retained these traits ever since. NPCs would mention them in dialogue as useful for anti-dragon weapons for Lao Shan Lung and Fatalis. As other comments have noted, the Dracophage bugs with Stygian Zinogre eat dragonfell berries, but Stygian itself also has dragon element within its body and the bugs are not the only ones using it. Beyond that there are still other dragon-using non-elder dragon monsters like Akantor, Scorned Magnamalo, and others in spin offs like Doragyurosu and Anorupatisu in Frontier. There’s basically nothing suggesting that dragon-element (or more literally from Japanese, “dragon attribute”) is a virus or bacteria, and this doesn’t really make any sense, since even if it were that bacteria or virus would need to be using unknown forces to affect other elements… in which case those unknown forces would need a name. Like “dragon element”, lol. I’m not sure why this is such a widespread idea-it’s not like fire, water, ice, and lightning have anything to do with biology in terms of idea/concept, why would dragon element? They might be produced biologically, but they are not biological substances, they’re forces of nature, phases of physical matter. Dragon element shouldn’t be any different.

Incredible video

This is what I thought in bloodborne about cosmic celestial beings and thanks I'm not the only one who thinks elder dragon that came out from nowhere that usually adapt and evolves depends on a environment they're living and has a instinct to survive the ecological system in the new world.

My theory has been for awhile that the Dragon element is a form of radiation that may come from cosmic rays or maybe it was made/used by the ancient civilization and then started leaking into the world and maybe that's why the ancient civilization fell.

I hope not, because its literally the most used "plot twist" in japanese media for some reason, I can name soooo many japanese anime, manga and videogames that drop the "it was aliens all along" plot twist. They do love aliens over there it seems.

Wdym Alien ?????? Nergigante basically gigantic angry Palico & Velkhana basically a Ice Dog who been Hibernation too long.

0:57 Higher Oxygen levels makes bugs and other arthropods grow huge but not vertebrates(land animals) Bugs breath through defusion. This type of breathing limmits the size of the arthropod to the level of oxygen in the investment. Vertebrates(land animas) breath actively through their lungs and arent bound to the limitations insects have. They only have a size limit based on how heavy they can be before they can't support thiere on weight on land anymore.

King ghidora is an elder dragon also excluding tempered monsters this might be why scoutflys turn blue around elder dragons

i have a question, what are the dracophage berries then?

I personally think that while not all elders are alien, for example Lao Shen Lung could just be effectively the monster hunter equivalent of a lizard landfaring whale, I think that the black dragons are specifically descendant from Safi Jiva as an ancestral species. Safi Jiva might be a doomed species depending if there aren’t vast quantities of bioenergy and as a result, they speciate in different ways without access to high amounts of it, fatalis becoming a fire specialist black dragon, alatreon and disufiroa are likely closely related and specialize in using various elements to overwhelm any rivals, so on and so forth. In reality the xeno and safi we fight are probably the only ones of their kind in a long time to show up on earth due to the comet/meteor that’s shown in the intro of the game.