Inspired by GoT, I wanted the dragons of Arcadia (the world I'm building) to have their fire breath in the most biological way possible. By this I mean that fire will not be magical, technological, nor through ingesting stones rich in hypergolic gases or chewing stones to generate sparks. Through a gland, dragons produce a flammable oil from the fat of the animals they eat. To release the oil, dragons have two holes in the corners of their mouths. To ignite the oil, dragons first release charged oil droplets under an electrical arc of about 1200 volts (as dragons are of dinosaur proportions I don't think this will be a problem), this creates initial flares to ignite the jet of oil. that comes right after. But it is still open what this oil would be made of, what components(and i think just saying that oil is flammable is somewhat vague information).

What would be the ideal chemical composition to help create an efficient exothermic reaction?

Details for those who want to create a well-constructed answer: highlight every component that may be in the oil, every acid, salt, etc. The important thing is that all components must be obtained through a meat-based diet. The diet is not limited to one type of meat, dragons can eat cow, horse, whale, fish, birds, humans... Any type of vertebrate that is not poisonous. I intend to make a variety of species, so if I can talk more about a mixture for oil (with variations in potency, of course), it would be very helpful.

  • $\begingroup$ immediately 1 name came into my mind... napalm and i bet your dragon likes to crew on styrofoam ;D $\endgroup$
    – user6760
    Dec 16, 2021 at 9:20
  • $\begingroup$ All fatty acids are flammable. Humans have been burning vegetable and animal oils for millennia; think candles or of any oil lamp. Just look up common fatty acids and check their melting points, to be sure they are liquid at low-ish tempeatures. For example, palmitoleic acid is melts at −0.1 °C. $\endgroup$
    – AlexP
    Dec 16, 2021 at 9:39
  • $\begingroup$ Um, the name of Arcadia has already been taken, by the Trollhunters franchise. Might want to change that name. $\endgroup$
    – Alendyias
    Dec 17, 2021 at 2:05
  • $\begingroup$ Why? This word is not copyrighted. It's a region of Greece that in mythology was home to the god Pan, it's not like the trollhunters franchise invented that word. $\endgroup$ Dec 17, 2021 at 2:49

3 Answers 3


Sebum, beeswax, tallow, basically any fat is a good combustible, as you might know if you have ever tried to grill some fatty meat.

Probably the most suited is spermaceti, because it's both combustible and liquid above 30 C

Raw spermaceti is liquid within the head of the sperm whale, and is said to have a smell similar to raw milk. It is composed mostly of wax esters (chiefly cetyl palmitate) and a smaller proportion of triglycerides. Unlike other toothed whales, most of the carbon chains in the wax esters are relatively long ($C_{10}–C_{22}$). The blubber oil of the whale is about 66% wax. When it cools to 30 °C or below, the waxes begin to solidify. The speed of sound in spermaceti is 2,684 m/s (at 40 kHz, 36 °C), making it nearly twice as good a conductor of sounds as the oil in a dolphin's melon.

Cetaceous lamp oil was a commodity that created many maritime fortunes. Measurement of the proportion of wax esters retained by a harvested sperm whale accurately described the age and future life expectancy of a given individual. The light produced by a single pure spermaceti source (candle) became the standard measurement of "Candlepower" for another century.


I tried making a pumpkin flamethrower once. Used a candle where a spray can would blow past the candle and ignite. Had a hard time figuring out what would actually work for a flamethrower. Tried hairspray, tried halloween hair coloring. (Hair coloring spray is made up of nearly 100% flammable ingredients by the way, but I digress.) The flamethrower would always blow out the candle, and blow up too close to the pumpkin. So gas alone won't work.

What did work was WD40, a lubricant found in nearly every hardware store in the USA. It would shoot out 3 feet/a meter and produce a nice flame. So some kind of atomized/flammable oil would work. Ideally you want it to stick to continue to cause damage, otherwise the target will just be scorched.

For the igniter you would want a compressed air effect. It's the same effect that makes spaceships super hot as they enter the atmosphere - common lore says that the heat is because of friction, but it's not.

Methane is the stuff of farts, and could be used to cause an explosion within the throat to propel the flame far. Bigger dragons have bigger throats. Mixing the methane with water vapor or whatever might help slow down the explosion so it's more of a continuous flame. Controlled methane explosions probably don't convey enough heat to injure the dragon. The spray can flames only singed the hair off a hand when it caught me by surprise.

So to recap you want:

  1. A way to ignite
  2. A controlled explosion or lung power (or both)
  3. The flame to not reach full intensity near the dragon.
  4. Residual damage so the target gets cooked instead of just singed.

Also, there's side effects you can use:

  • Dragons have to learn to control all parts of the flame apparatus.
  • The force/suddenness of the flame could be controlled. A bigger/more sudden flame would be more scary/impressive, but because it's limited how the oil would be sprayed, would cause less damage.
  • Dragons could singe someone on purpose instead of cooking them, to show displeasure/be an asshole.
  • Understanding how this flame works means it's vulnerable to being interrupted. For example, getting any of the napalm ingredient in the bellows/explosion could burn the dragon, they'd have to hold their breath or something to put out any flames inside.
  • $\begingroup$ Well, it wasn't a bit of what was asked in the post, but thank you very much. Unless WD40 can be produced or synthesized by an animal's body. $\endgroup$ Dec 17, 2021 at 2:54
  • $\begingroup$ "So some kind of atomized/flammable oil would work." $\endgroup$ Dec 18, 2021 at 18:43
  • $\begingroup$ I already know that, that's why dragons will produce oil from fat. Unless you explain what something atomized means, it's still nothing like what was asked in the post. $\endgroup$ Dec 18, 2021 at 23:25


Dragons love alcohol. It's a nice flame.. Formation of the alcohol takes place in the dragon's stomach, which is compartimented. To prepare for using flames, like on a battle field, or for mating purposes, the dragon will digest, stack and compress large amounts of blueberries and grapes and let them ferment, weeks before the event. Sugar is converted to alcohol quite effectively. The resulting alcohol is spit out with a hickup, mixed with fat and other easy combustable substances.. and ignited by ways of teeth grinding

(note: the grinding is a recent find, much knowledge of dragons is still under development & ongoing field research !)

  • $\begingroup$ All my dragons are carnivores, this is not viable and it's a bit off the subject of the post. I'm not looking for alternative ways for my dragons to produce fire. I just want to know what would be the ideal chemical composition for an oil to have to produce a good exothermic reaction. $\endgroup$ Dec 18, 2021 at 2:23
  • $\begingroup$ Don't worry @WizardKing, dragons are carnivores. The substance is ethanol.. and I don't do answers with hand waiving, the ethanol originates from somewhere. The stomach compartiment of the dragon is a challenge in this case, because the process creating the ethanol must be very effective to make the fluid combustable ! So this answer does does need some hand waiving. But the grapes are for free. $\endgroup$
    – Goodies
    Dec 18, 2021 at 11:33

You must log in to answer this question.

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