Dragon Stuff

Firebreath in general
Firebreathers have glands located at the back of their mouth that can expel two different chemicals, which when combined creates fire.

MudWing firebreath
MudWings can't breathe fire unless they're a certain temperature. This is due to them having muscles that are usually relaxed, blocking off the flow of the two chemicals. When the MudWing reaches a certain temperate, the muscles will contract which allows the chemicals to be expelled.

Frostbreath
IceWings, like the firebreathers, have glands at the back of their mouth that can expel two different chemicals. But in the IceWings case, the chemicals, when combined, create an endothermic reaction instead of a exothermic one, sucking the heat out of anything it touches.

Venom
Through eating alkalizing fruit enzymes found in a RainWing's body break it down and extract the base and send it to the venom sac. The venom sac produces specialized cells to store the base, along with a fluid to lower viscosity, making it easier to pump through the fangs, and help the cells get to their target. Whenever a venom cell encounters something new it will do a DNA check. If the DNA is very similar or there isn't any at all, the cell will stop/not start excreting the base. If there is DNA present but it's not alike the cell's own DNA enough, it will release the base and harm the victim.

Full copy and paste of the page info One day I started wondering about the component makeup of RainWing venom. Curiosity and a need to procrastinate lead to some web research on how matching effects could occur here on Earth, along with some data checking from the books. Eventually through many, many articles and plenty of eye strain, I found a way to describe the internal workings of RainWing venom, which I decided to share, 'cause screw my math homework. Keep in mind this is my own interpetation of it, and DEFINTELY ISN'T CANON. Heck for all we know it was an animus spell or something. Regardless I'll give my two cents on it.

I'll start with an interesting fact about RainWing venom, that it will only harm biotic material (anything that is or used to be alive) and will do nothing against non-biotic matter (rock, water, dirt etc). If you think about this, you'll come to the conclusion that RainWing venom must be BIOTIC. After all, most substances don't discriminate, and will just as happily harm your hand than metal.

But that raises another question. If the venom is alive how does it sizzle and melt on contact? The key word here is melt. It's not some kind of natural acid, (Like the diluted hydrocloric acid in your stomach. Isn't science grand?) as acid BURNS. BASES however, materials with a high pH level and the literal opposite of acids, DO melt things. Multiple times in the books victims to venom attacks are described to have their scales melt, which confirms it's not acid. (Book 1 Fjord's death and Queen Scarlet).

Specific organs are capable of creating alkaline liquids. The liver is one. It makes bile, a slightly alkaline liquid. An even better example is pancreas juice, a mixture of various things used to help break down food and absorb nutrients. The pH isn't very high though, it will barely melt anything. Of course RainWings can very well have a gland that only produces what makes the juice alkaline, raising the pH potentially to make it a viable weapon.

But wait. We can do better. Multiple foods are more alkaline than the stuff in your body, and quite a few can be found in a rainforest. I chose to go with this one because it made SO MUCH SENSE. So the RainWings have something that extracts and stores the alkaline substance from their food, likely a subsection of the small intestine, the same place where vitamins, proteins, and other nutrients are extracted from food.

That was the simple part to research. The trickier bit was finding out how the alkaline was delivered to a target. After a bit of research it seems the most likely possibility is a highly specialized cell, similar to a red blood cell, that carries the alkaline liquid inside of it instead of oxygen. The cell and millions of others are suspended in a fluid that sustains and provides an ideal environment for them, much like plasma in blood. The venom is stored in a sac somewhere in the head ready for use, and can be forced out by muscles to a long range attack.

Upon meeting organic matter the cell will dump its payload, dousing the target in a highly alkaline substance that would melt them. When the cells encounter other cells, that is, anything that is or used to be alive, it does a DNA check, making sure its victim isn't a close relative. If it meets another venom cell who's DNA IS close enough to be considered a relative, the cell would stop secreting the base, preventing further damage. This is why RainWing venom immediately stops after encountering a relative's venom, and why in book 3 Kinkajou was still wounded, but not further, when Glory applied her venom onto Grandeur's.

So a summary of what happens. Through eating alkalizing fruit enzymes found in a RainWing's body break it down and extract the base and send it to the venom sac. The venom sac produces specialized cells to store the base, along with a fluid to lower viscosity, making it easier to pump through the fangs, and help the cells get to their target. Whenever a venom cell encounters something new it will do a DNA check. If the DNA is very similar or there isn't any at all, the cell will stop/not start excreting the base. If there is DNA present but it's not alike the cell's own DNA enough, it will release the base and harm the victim.

Source -

Fangs
RainWing fangs, like spitting cobra fangs, would have an L-shaped venom canal instead of a venom canal that follows the shape of the fang. Their venom compressor muscle would also be very strong so that it could spit the venom instead of inject it. Their fangs would also be able to be folded back into the RainWing's snout, which would stop them from stabbing themselves.

Source