Terrestrial Dragons, usually just called Dragons, are the Dragons that live in, on or close to The World That Is. This distinguishes them from their much larger cousins: the Galactic Dragons.
Within this group further subgroups can be identified, relating to the element in which these creatures move. Thus you have air/fire dragons (“normal” dragons as everybody knows them), water/fire dragons (also known as scions of the deep flight) and earth/fire dragons (a rarely seen subgroup associated with volcanoes, they have refined temper tantrums to a catastrophic art).
All Dragon species were originally created when some the Ancient Gods combined with the base element Life. As such they are closely related to the New Gods and the Titans (see Creation). Unlike either of these, however, the Terrestrial Dragons learned to reproduce.
A Dragon child (called a drageling or whelpling) hatches from an egg after an incubation period that varies wildly (between mere months and centuries). For the rest of its life, a Dragon keeps growing and accumulating knowledge.
Since they can control the Void inside them, most dragons are immortal in the sense that they do not die or even weaken from age. They can be killed, but unless the dragon is very young or you have a very strong army … don't try.
As they get very old, usually after several thousands to ten thousands of years have passed, Dragons grow melancholic and slowly succumb to the grind of life by going insane. Many of them prevent this from occurring by taking their own life before this can happen. Some others are hunted and killed by other Dragons.
Though a certain variety exists (especially between species), Dragons tend towards a Lizardlike appearance. This is certainly no coincidence although scholars disagree whether the first Dragons formed their shape after lizards they met in the World That Is, or rather that lizards were created by dragons in much the same way the New Gods created humans. Their size is primarily dependant on age, with a newborn drageling measuring roughly the same as two adult cats and an ancient wyrm measuring roughly the same as a small castle. It is unknown just how large a Dragon can become although celestial dragons (not native to The World That Is) are often mistaken for galaxies.
The best-known Dragons, these resemble large winged lizards. Usually they have four legs and two wings. While their hind legs are usually very muscular, allowing them to jump in the air to facilitate lift-off, the front legs are more precise and could often be considered arms.
Flying and Breathing Fire
Physiologically, air/fire dragons have a very lightweight build. Their bones, scales and in fact most of the rest of them, are made from very light (but strong) materials that do not form naturally but only through fire magic, which dragons have a great deal of, since their primary element is fire (if you read the creation myth you know that the first dragons derived from the ancient gods, as such they are in fact brothers and sisters to the World That Is and contain elements the latter does not). Their natural affinity towards fire and fire magic gives them a great deal of control over this force which they can use, amongst other things, to combust air (breathe fire).
Dragons also have very big lungs (the better to fry you with, dear) and they can superheat the air in there to make themselves lighter yet (like a balloon). This brings their weight/density within the range that they can use their wings to fly. On top of this, dragons will sometimes use magic to improve their speed and manoeuvrability (dragon magic is strong, and gets stronger with age).
It should perhaps be noted that the whole firebreathing thing is a side effect of flying. The main use of it is to expel the super-heated air from their lungs so they can go down (like a ventile on a balloon). However given the usefulness of being able to fry anything, many dragons have evolved a second, much smaller air chamber where they can compress or store the hot air so they can breathe fire without losing altitude (and vice versa). Flames from this second chamber tend to be a lot more violent due to the compression.
Found in the oceans at any depth, these Dragons do not require air for .. well, anything. They are made from similar alien materials as their air/fire brethren except that in their case weight was not as much an issue. Since they have no compressible gasses in their physiology, they can change their depth much faster than nearly any other living creature.
Physically they resemble air/fire Dragons minus the wings and with far less pronounced legs. They usually have long fins that traverse their entire bodies which they use to swim at incredible speeds. In fact swim is not a correct word, as their high body temperature boils the water around them, allowing them to “fly” in the water vapour. Due to the shape of their bodies, his water vapour provides an extra propulsion force.
Living underground, very little is known of these rarely seen creatures. Usually their presence is only found out about when they suddenly blow up, causing widespread carnage to the lands.