Dragons were actually warm blooded creatures but laid eggs to reproduce. They mate in mid air. They usually have wings and thier bones are hallow for lighter weight to enable flight. Dragons live from 500 to 1000 years with Man being their only enemy. Their bite averages a pressure of 2 tons...and could have gnawed steel. They could fly very fast but could not run at all do to their muscular build. Their bodies were completly covered with tear shape scales, except sometimes the neck and stomach, and can be made to stand on end for pruning. Instead of sheading scales they keep growing like human nails and are not lost except for accident or disease. Their saliva had very strong adhesive properties.
The fire breath of a dragon is casued by gases. When we eat our body by digesting created a gas know as Methane (CH4), dragon unlike human and other animal store this gas into another kind of "lung" that will serve as a bag/canister to held the gas that will be later mixed with a small amount of phosphor (P43) that has the propriety to ignite in fire at the contact of air. When the dragon wants to breathe fire, the methane is release into the lungs and when the gas is in the air, the phosphor ignites and lights the methane in fire.