In a previous post, I asked about dragons in my stories and how I could make it plausible for them to fly while also meeting the criteria of having 6 limbs and being 15 to 20 feet long when fully grown. Recently, I’ve been considering going back to this question.

This time, I intend to actually listen to the feedback, but first things first, here are some criteria that I want everyone who answers this to consider:

  • The dragon must have 2 arms, 2 legs, and a tail of at least medium length.
    • The dragon must be capable of using its arms to support itself when it is not airborne.
  • The dragon must have horns and teeth of some sort.
  • The dragon’s peak flight speed must be at least 20 mph.

Also, to make myself clear, the dragons of my stories don’t have to be 100% classic dragons in terms of how they’d look. The following image was included in the answer to the previous version of this post, and I actually liked it: enter image description here

It just didn’t fully satisfy my needs. Ultimately, I want to blend mythology and science for my dragons. That said, be creative; the arms could be designed with small, secondary wings that fold out when flying and I would hardly bat an eye (that said, I’d prefer to avoid that.)

Also, since the title says “how could I redesign”, here’s what the typical dragon of my stories looks like currently:

enter image description here

  • $\begingroup$ Birds can fly and are descended from dinosaurs. Dinosaurs are kinda like dragons. Evolve your dragon to be more like birds. The first thing to go is size unless they drink gasoline. $\endgroup$
    – DKNguyen
    Dec 5, 2023 at 16:58
  • $\begingroup$ Can the planet's atmosphere be different? If it is more dense, it'll be easier to fly. $\endgroup$
    – Mathaddict
    Dec 5, 2023 at 20:21
  • $\begingroup$ @Mathaddict I’d say so, but not enough to really matter effectively: in my stories, these dragons aren’t from Earth, yet they can still fly on Earth. $\endgroup$ Dec 5, 2023 at 21:42

3 Answers 3


NO dragons to date can plausibly fly. They all use magic/handwaving to fly. Lots of dragons don't even have wings. Your dragons can follow that time honoured theme, the number of limbs makes no difference.

If you want yours to use no magic then design them along the lines of a bat, chuck an extra pair of legs on, and have them produce buoyant gases internally like some fish do to make them much lighter. That way they can sustain 20-30 metres of dragon against gravity while sculling through the air using their wings. If their equivalent of a swim bladder is controllable they can release some gas to plummet and pick up speed etc,. Add some to go higher and all the rest. It would make a fun creature to play with.

  • $\begingroup$ I read this question more along the lines of making the Dragon Anatomically plausible TBH $\endgroup$ Dec 5, 2023 at 2:35
  • $\begingroup$ @TheDemonLord which is what I did in the second paragraph. If they want 6 legged anatomically correct in Earth terms, then go for an insect dragon. Because there is zero classic dragons that can plausibly fly $\endgroup$
    – Kilisi
    Dec 5, 2023 at 2:36
  • $\begingroup$ @Kilisi I feel like you aren’t really giving this a fair attempt. What you’re describing is, as I’d call it, a “glorified pterosaur”, and on top of that, you’re saying no classic dragons can fly, when there are types of classic dragons that probably have the potential to fly, such as Wyverns. But that’s just my perspective. $\endgroup$ Dec 5, 2023 at 21:49
  • $\begingroup$ @GodzillaLouise you should build an answer around your Wyvern theory, I look forwards to reading it $\endgroup$
    – Kilisi
    Dec 6, 2023 at 6:09
  • $\begingroup$ The buoyant gas idea has been used by exactly 0 real-world flying creatures. $\endgroup$
    – Monty Wild
    Dec 8, 2023 at 1:56

15 to 20 feet, or 5 to 7 metres with horns and teeth is quite a stretch for a flying animal in Earth's gravity and atmospheric pressure, but it is not completely impossible.

The most capable flying creatures on Earth are around 1kg in weight at most. Larger fliers are less capable of rapid manouvres, and require a run-up in order to take off.

Supposing that we could have a vertebrate animals that, by some genetic happenstance, mutated to have an extra pair of functional limbs at some time in the distant past. Unlikely, but not impossible or beyond the bounds of belief. That at some later point, one set of limbs - probably the centre set - evolved into wings. At this point, we have a flying creature that has four legs and a pair of wings. It is probably quite small, no bigger than other early fliers, probably in the sub-1kg range.

At this stage, the flying critter needs to be a carnivore. It would hunt by flying around and swooping down upon its prey, grasping it with its front limbs and biting it, then chewing it up before swallowing it.

Once these critters have evolved to be good fliers, and various populations have diverged from one-another, one population might evolve to have mate selection criteria that favours horns and great length, displayed in flight, possibly with an offering of prey, possibly with a display of teeth. The thing with sexual selection is that it can justify the most outrageous adaptations, because if another critter has bigger and sexier traits than you, they get to breed and you don't.

So, we have sexual selection for horns, long, flying, predatory and teeth, for this creature. We also have the purely physical selection criteria that flying creatures must be light. These selection criteria would favour critters that meet all six of these criteria. As the mass of the critter goes up, we can retain all four legs, as they will be necessary to propel it along the ground in its take-off run-up, and they serve a purpose in prey capture.

Now... how to make it really big? Sexual selection will help, since in sexual selection, the gender that expends the most energy in reproduction, usually female, can be choosy and will select only the mate that best fits their selection criteria. Over the generations, these critters will stretch out, becoming bigger, but also longer and thinner.

So, what do we end up with? Our dragons will be 15 to 20 feet long, but they'll be thin like snakes, with torsos that are narrow from side to side, but thicker vertically, to allow for the bone and muscle necessary to support their bodies. The spine would be muscular, as this creature would likely bound like a mustelid when making its run-up ass a precursor to flight. The limbs would be short and muscular, with grasping claws, to retain functionality while minimising weight. The bones will be hollow and light like a bird's. They will be muscular around their torso where the wings connect, to power its flight. The neck will be long and serpentine, and the head will be light. The horns will look big, but will be hollow and very light, and probably a different colour that screams 'Look at these!' The teeth must be functional, as this critter is a predator, but in order to lighten the head, the head is likely to be tall and narrow, to allow the maximum necessary biting strength at the minimum weight. The snout would be short, more like a cat's, as this is likely a sight-hunter which has little need of a long nose to support a good sense of smell. The eyes would be large and forward-facing, befitting a predatory species.

The largest flying species on earth is thought to have been Quezalcoatlus northropii. It is debatable as to how much they may have weighed, but it is reasonable for this dragon to weigh in the range of 70-100 kg.

With this size and these adaptations, these dragons would likely hunt small to medium-sized animals, probably around 10 to 25 kg. They would likely be unwilling to tackle a human-sized animal as prey, and would likely flee from a single adult human. However, small children would likely present the temptation of an easy meal.

  • $\begingroup$ Hm. This is a much more workable answer for when I get to the design process than the other two were. This will definitely be the answer I go with for the bounty, but first I need some animals to use as references. So, what would you suggest I go with? $\endgroup$ Dec 8, 2023 at 3:23
  • $\begingroup$ @GodzillaLouise What do you mean by references? Look at ferrets, weasels and polecats for the elongated torso and short limbs, snakes for the long narrow body and head, birds for the tall, narrow face and head. $\endgroup$
    – Monty Wild
    Dec 8, 2023 at 3:27
  • $\begingroup$ Yeah, that’s exactly what I meant by references. Thanks. $\endgroup$ Dec 8, 2023 at 3:31

Think Genes and Evolution

If you would like it to be scientifically plausible, you need to go back to fundamental scientific principles.

The process of evolution has produced a marvellous range and variety of life on Earth, but keep in mind that all life is hereditary - and traced back to common ancestors who can then be traced back to other common ancestors.

In your situation I would suggest looking first at evolutionary pressures that cause mutations in existing animals to then become advantageous - e.g. allow more babies to be born. This starts the process of speciation, and slowly forms your desired end result (keep in mind there is no 'master plan' in evolution and each increment of a species is advantageous at the time).

Pressures that could assist you could be:

  • Sexual Selection: One of the major pressures. A female only pairs with a male when she sees certain attributes she considers advantageous - and thus helps her kids. This includes plumage, colours and behavioural attributes also and that may actually not even serve a purpose (in fact, not having a purpose is sometimes desirable as it signals that a male must be so comfortable that not having a purpose is possible - think Peacocks).
  • Environmental: Pressures in an environment may allow some to have babies more than others - for instance breeding and perching on cliff faces being more protected than out in the open on plains where predators can eat eggs. This indeed may be one of the main reasons why flight evolved.
  • Competition: Not all males can mate with all females - there would presumably be some male to male competition. This is where horns, defence mechanisms and claws mostly come from - the warding off / defending of your territory against others of your own species to ensure you have more babies.
  • Survival Pressures: Perhaps a whole lot of part of species dies and leaves ones only with certain attributes to survive - many attributes of animals today are from simple survival pressures, mainly access to food, and safe environments.

So your dragon needs to be 'reverse engineered' evolutionarily to exist. I would suggest:

  • Basing the original species off Reptiles - as these lay eggs, and have many original attributes suitable for your story.
  • You need additional limbs - keep in mind for a 6 legged dragon you need an additional 4 limbs (2 x for wings). This is quite hard actually as it is difficult to conceive of pressures that are strong enough to create complexity - especially that of additional limbs. I would use the example of bats, which create wings using elongated fingers - ie using existing appendages. Perhaps toes become additional rear limbs to allow easier perching (much like opposable claws) initially, with fingers of upper limbs becoming wings. Over time, the split in toes grows, and so does the split in wings - but they are actually fingers and toes that grow into limbs.
  • Competition and Sexual Selection provide the pressures for colorisation (in your sketch), tail length and horns. All these attributes have been achieved in existing species today.
  • In terms of flight: there must be an advantage to grow big as doing so is very risky and evolutionarily difficult (ie. it is much easier to be small and have a lot of babies). However, large animals tend to become more advantageous with food sources that are not attainable by small ones - filter feeders, or bountiful sources far away not reachable by competitors - such as distant islands. Once this is established, it is easily conceivable that wingspan and weight are optimised to reach distant food sources or match migration patters that ensure only large sizes are able to do so.

Once the need is present, then evolutionarily the species tends to optimise bone density (ie, very very light bone density), organ placement / deletion, lightweight flight surfaces (thinner membranes), lighter cranial structures etc and even genetic memory and learned techniques such as riding thermals to shed weight and allow flight to be easier for less effort (and achieve more babies).


You must log in to answer this question.

Not the answer you're looking for? Browse other questions tagged .