Though a winged creature, the dragon is generally to be found in its underground lair, a cave that identifies it as an ancient culture of earth. Likely, the dragons of European and Mid-Eastern mythology stem from the cult of snakes found in religions throughout the world.
In Western folklore, dragons are usually portrayed as evil, with the exceptions mainly appearing in modern fiction. In the modern period the dragon is typically depicted as a huge-fire-breathing, scaly, and horned dinosaur-like creature with leathery wings, with four legs and a very long muscular tail. It is sometimes shown with feathered wings, crests, fiery manes, ivory spikes running down its spine and various exotic colorations. Iconically it has at least combined the Chinese dragon with the western one.
Many modern stories represent dragons as extremely intelligent creatures who can talk, associated with (and sometimes in control of) powerful magic. In stories a dragon's blood often has magical properties: for example in the opera Siegfried it let Siegfried understand the language of the Forest Bird. The typical dragon protects a castle or cavern filled with gold and treasure and is often associated with a great hero who tries to slay it, but dragons can be written into a story in as many ways as a human character.
This includes the monster being used as a wise being whom heroes could approach for help and advice, so much so that they resembled Asian dragons rather than the European dragons of myth. Roman dragons evolved from serpentine Greek ones, combined with the dragons of the Near East, in the mix that characterized the hybrid Greek/Eastern Hellenistic culture. From Babylon, the musrussu was a classic representation of a Near Eastern dragon.
John's Book of Revelation-Greek literature, not Roman describes Satan as "a great dragon, flaming red, with seven heads and ten horns." Much of John's literary inspiration is late Hebrew and Greek, but John's dragon is more likely to have come originally through the Near East. Perhaps the distinctions between the dragons of western origin and Chinese dragons are arbitrary, since the later Roman dragon was certainly of Iranian origin: in the Roman Empire, where each particular identifying signum (military standard), after the Dacian Wars and Parthian War of Trajan in the east, the Dacian Draco military standard entered the legion with the Cohors Sarmatarium and Cohors Dacrum (Sarmatian and Dacian cohorts)- a large dragon fixed to the end of a lance, with large gaping jaws of silver and with the rest of the body formed of colored silk. With the jaws facing into the wind, the silken body inflated and rippled, resembling a windsock.
This signum is described in the surviving epitome of Vegetius De Re Militari 379 CE: "The first sign of the entire legion is the eagle, which the eagle-bearer carries. In addition, dragons are carried into battle by each cohort, by the 'dragoneers.' "
I hope to do another "Dragon" article very soon-perhaps tomorrow if I get a chance. I believe all of this information so far is from the "main" dragon section of Wikipedia and the "European" dragon section-I thought it would be good to have a lot of background for the next part. Thanks again for all of your wonderful comments!
The first image is a painting by Viktor Vasnetsov called "Zmey" -the Russian word for dragon and the second image is of a Romanian 5,000 Lei bill with a dragon pictured on top of the buildings.