The dragon is a warm-blooded reptile with the ability to control its body’s temperature internally. This characteristic enables them to adapt to the different climates of their extensive habitat and to maintain his activities both day and night throughout the year, as he is not dependent on the warmth from the sun like the other reptiles. The dragon generally has wings, and his bones filled with hydrogen, for lightness (and fiery breath). There are records of dragons who have lived for five hundred and even a thousand years, but there are no knows cases of dragons who have died from old age. On the other hand, they died from accidents, certain diseases, or as a result of the actions of their most relentless enemy: MAN.
  The Skeleton
The dragon is the largest known flying creature. Their bones are hollow and contain hydrogen, produced from eating bones, to maintain their enormous bulk in the air. Their wing bones fit on to broad shoulders which support the powerful wing muscles, which require an extraordinary articulator system unknown in other species. Their bones are tougher than reinforced concrete and much lighter. Dragons can fly well and with great speed.

 The Muscular system
The dragon’s muscular system is fascinating and complicate. I evaluate the power in the bite of a dragon to put to an average of 2 ton per cm cube (i.e. It could easily gnaw steel). Dragons are very powerful. Their leg and arm can support great charge without much difficulty but this only applies on ground movement because in the air, a dragon could not maintain more than half of is weight for a long period of time. The muscles on their legs and arms were not suited for running, but they could walk (With the many different mutations Dragons have undergone, it may be possible that some species of dragon could run.)
 

  The Scales
most species of Dragon's body’s are completely covered with tough, shiny scales. As dragons love adornment they stick precious stones and other jewels to their neck and stomach, which also act as added protection. They stick these jewels on using their saliva which has powerful adhesive qualities. Dragons often wear jeweled breastplates to protect their soft abdomens. The scales are pentagonal, and shaped like a teardrop, with two long sides and two shorter ones, and a very short fifth side attached to the skin. The dragon can make them stand on end whenever he likes to preen them. The dragon is a very clean creature and takes great care always to keep his skin and scales clean and immaculate, much like a cat. In their normal position, the scales overlap very neatly and, thanks to a tiny cavity in the surface, they fit into each other to allow perfect freedom of movement. Scales have the following characteristics:

• The innermost part is composed of a compact hairy formation firmly rooted in the epidermis.
• On the hair follicle there are some tiny glands which secrete a substance that adheres firmly to the skin.
• This substance is rich in minerals, which determine the hardness and the color of the dragon's scales.
• The external surface has a horny, translucent texture, which gives the scales their habitual luster.

A dragon does not need to shed his skin like most other reptiles. As the scales grow they are renewed automatically, like human nails and hair. They are not shed from the body, except rare cases during illness.

  Coloring
It is impossible to list the enormous variety of hues that make up the dragon's brilliant coloring, but they can be divided into three broad color groupings:

• Blues, ranging from dark blue to silver and mother-of-pearl.
• Red, ranging from copper-red to dark red and reddish-black.
• Greens, which include every imaginable shade of green and yellow and even dark brown, emerald green and burnished gold.

Although these three principal color groups are not usually mixed, a dragon's coloring is rarely uniform. In general, their scales are several hues from one of the main color categories, with a metallic luster which is hard to define. When the scales have a pale or opaque it is a sure sign of ill health. Many dragons are known by their scales, such as Ancalagon the Black, Smaug the Golden and Spars the Green.
 

   Large or Small?
For many of you, the word "dragon" means a huge, enormous or imposing creature, such as is portrayed in fairy tales. Dragons are more likely to be small creatures (from 1 foot to 10 feet long).

To prove this theory I will attempt to explain a principle of physics called "Physics of Proportion" or "Physics of Lilliput".

First, you look at a cube (1cm x 1cm x 1cm). If you decide to double the length and you want to keep the proportion you will have a bigger cube (2cm x 2 cm x 2cm). The length of the enlarged cube will be multiplied by 2, the surface will be multiplied by 4 and the weight/volume will be multiplied by 8. Well let’s say that a bird needs to have a wing span equal to his body length to fly. Enlarge this bird ten times. There will be 100 times more surface. However he will weight 1000 times more and since his wings give him the power to fly and that these rely on the surface and not on the volume, he will be unable to fly for his lack of lift power.

A large creature could have some difficulties flying, but we haven't proof they cannot exist. The second thing is the structure of the dragon. Some people believe that Dragons have cartilage instead of bones but this could only be possible in very small creature. The shark, for example, lives in water and in water your apparent weight is much lighter than in air that explain why an animal like this could live with only cartilage. Look at your nose and you ears. These are made in cartilage but as you have surely notice, this isn't very strong and it could not support the weight of your entire body. Now if they cannot be made with cartilage, they are obviously made with flesh and bones but the fact with bone is that they rely on the surface (i.e. diameter and not superficies) to be strong and large bone increase the mass and thus make the flight much more difficult.

It is true that the hydrogen in Dragons bones allow them to gain more lift and makes them lighter, but this would still not be enough to enable a very large Dragon to fly. It is more realistic to say that dragons are small creatures if you consider that they can fly otherwise, they will follow the same principle in the structures of these huge magnificent reptiles, the dinosaurs (in this case their wings would be absolutely useless).

(Summary of the "Physic of Proportion": The rule is simple, when you change an object proportionally, the change "A" affect the dimension as this: the length=A, the Surface=2A and the Volume=3A.)

  Reproduction
The reproductive system of these creatures is internal, which means that it is nearly impossible to determine if a dragon is a male or a female, only the general behavior and the small change in their color can provide information about the dragon's gender. Dragons lay eggs like reptiles and birds. The eggs are protected by a hard shell that with time will weaken to let the new baby dragon break it more easily. The incubation period of these creatures is mostly unknown; some eggs will hatch in a year, others two and some more than five years (hence the dragons endangerment). The dragon’s eggs are rich in calcium and the newborn dragons eat it so as not to waste the nutriment in it.

The mating process is known as dragon-slide: the two partners fly high in the sky and after a moment they grab each other and close their wings and make free-fall. Then at less than a hundred feet from the ground they open their wings and land. The dragons unusual mating process is mainly because dragons love speed and risk, and add these to the pleasure of love... you have a sensation that humans could never enjoy. (Sound like fun? Then you should have been born a dragon).
 

   Society
Dragons tend to be loners by nature or by obligation, we can say without a big inaccuracy that dragons are not very populous on Earth, few people have been lucky enough to see dragons. Dragons pass much of their time alone in their lair. During this time, they learn about their environment and how to use it wisely. Because they are alone a great deal of time, most of them enjoy company of other dragons and even human as long as they come in perfect love and trust. It may be possible that dragons have some sort of council lead by an elderly dragon but this yet has to be proven.

   Dragons and Mankind
Throughout history dragons and human beings have been unable to live peacefully side by side. As a result, mankind has not been able to benefit from ancient dragon knowledge. Man's craving for power and religious beliefs have kept the world engulfed in interminable and bloody struggles. The dragon lords could not understand the reasons for man's self-destructive behavior, and kept well out of the way, retreating to remote hiding places far from all this confusion. Shrouded in mystery, the dragon's trail remains lost in the obscurity of legend. However, the dragons secretly pursued their quest for knowledge without completely excluding the human race, since they accepted and taught those few men who sought the essence of truth. We could wonder what would happen if the dragons revealed themselves to the eyes of all humankind... Would we be able to accept another form of intelligence far superior to our own or would we feel the need to fight those, who at the end, could come to our rescue?

Types of

Dragons

Dragons can be divided into three social classifications, based on their intelligence. Lesser class dragons are rather dim, beasts. Mid class dragons are just as intelligent as humans, and can speak in our tongue, too. Greater class dragons are mystics... the ones who protect the Earth in myth.

It is often thought that the lesser dragons are the smaller kind. As with all dragons the social classifications has nothing to do with their appearance. (I think there's a lesson for humans there!) The social classification of dragons depends on their skills and knowledge/wisdom. Lesser dragons are not necessarily dumb, but include those that are not willing to learn. These dragons tend to be more physical beings that prefer to act first and think about it later.

Mid class dragons are just as intelligent as humans (by this I mean they have the ability to think for themselves and to solve complex problems). They often learn a few languages and can speak in human tongue. They have harnessed the ability to travel the astral plane and can communicate telepathically. These dragons tend to be the linguists and engineers. They come up with the ideas for the lower class dragons to create.

Greater dragons are the mystics. They become bored with learning languages and turn to natural elemental magick. They have the ability to travel the astral plane and can mix with all creatures. They communicate telepathically and have excellent knowledge of mathematics, astronomy and magick. In Eastern mythology they are the protectors of Earth and the ones that bring the rain and the sunshine. They are immensely proud beasts. Other talents of these dragons may include shape shifting, extended invisibility, telekinesis, divining and knowledge of the future.

There are also different kinds of dragons. The Chinese have five kinds of dragons. Imperial dragons have five claws (all others have four); Celestial dragons guard the heavenly abode of deities; Dragon spirits rule wind and rain and cause floods; Earth dragons clear rivers and deepen oceans; and Treasure guarding dragons.

In heraldry, a dragon with two legs is called a wyvern; a dragon without wings is a worm; a serpentine dragon with wings but no legs is an Amphiptere; a dragon with wings and legs is termed a guivre. Further meanings of these draconic images was determined by how the dragon was posed: rampant (forelegs raised), passant (one foreleg raised), stat ant (all four feet on the ground), wings endorsed (upright over the back), displayed or depressed, tail nowed (knotted). Even further definition was determined by the color:  gold, gules (red), sable (black), or vert (green).