Dragons

Dragons are a very rare race of supernatural creatures that have not been hunted or even seen for over 700 years. In fact, they are so rare that most veteran hunters (like Bobby Singer) dismiss their existence as purely fictional. Only a select few know otherwise, and even then, even they believe dragons were extinct. They are similar to the traditional dragons in lore, but, whilst in confined spaces, they appear more like humanoid creatures rather than the winged beasts shown in traditional art. There are descriptions of them appearing as giant bat-like creatures when in their true forms.

The dragons' motives were to open Purgatory to free Eve, Mother of All. To do this they abducted young female virgins so they could sacrifice one of them to become the vessel for Eve.

Characteristics
Dragons are attracted to gold and they traditionally live in caves, but they make homes or hideouts in sewers when there are no caves to hide in. In addition, it seems that dragons also are attracted to female human virgins and its implied they eat them. Dragons are also sapient and intelligent, to the point where they're capable of practicing magic. They are also social creatures who often work with members of their own kind. Although intelligent they are often very brutal when facing opponents and like almost all monsters have no regard for humans.

Physical Appearance
Dragons can take human form and can disguise themselves as a human. In their true form, dragons have large wings that they use to fly, they can hide their wings when disguised as humans. When flying their wings make a great leathery fluttering sound. Dragons also have large talons and snake-like eyes. When Dean sliced a dragon's arm, it showed a scale-like pattern, implying that they have scales in their true form. Dragons also have dark red blood.

In their true form dragons are quite large. One witness who saw them described them as "huge", the distance between the claws on one of their feet was shown, by the victim's wound, to be about two to three inches, thus implying it to be gigantic. Its wingspan is enough to cause reasonably strong winds by flapping them. Despite their size, they can move with incredible speed, agility and stealth through the air.

Powers and Abilities
Dragons are very powerful monsters, and have a number of abilities that make them difficult creatures to kill.
 * Super strength - They possess incredible physical strength. Dragons can easily overpower humans through sheer physical force. They are amongst the strongest of monsters, able to casually break bones, toss a grown man like a doll, and easily lift and carry a grown man, for over seven miles.
 * Shapeshifting - They can take a complete human form by shapeshifting, although when using their powers, part of their true forms become visible, specifically their snake like eyes.
 * Thermokinesis (also called "Dragon Claw") - They can also generate intense heat from their hands. These temperatures are hot enough to melt metals like iron, or even incinerate humans with their touch.
 * Flight - Dragons have bat-like wings which they use to fly and capture prey. They are incredibly capable flyers, able to move with great speed and maneuverability, and still demonstrate great stealth despite their enormous size.
 * Invulnerability - Dragons are near completely invulnerable; the only known way to harm or kill one is with a sword forged in Dragons blood. Significant other forces, such as repeatedly being hit with a iron crowbar, can daze them, but causes no permanent damage.
 * Super speed - Dragons can move with incredible speed, able to suddenly appear, almost like teleporting, especially when flying.
 * Super stamina - Dragons don't tire easily, they can fly miles at incredible speeds, and go through severe trauma without fatigue.
 * Super senses - Able to tell if a person is a virgin or not simply by getting close.

Vulnerabilities
The only way to kill, or even significantly harm, a dragon is with a sword forged with the blood of a dragon. Although there are only 5 or 6 of these special swords in existence as stated by Dr. Visyak.

It can be assumed that the Colt can be used to kill them, as it will kill almost any creature in existence.

Season 6
Dragons are abducting young women (all virgins) and keeping them captive in a sewer. Dean obtains the Sword of Bruncvik, and he and Sam track down the dragon's lair, finding first a pile of gold and then an ancient manuscript. They then hear cries for help and they follow the voices until they find the missing women, who are being kept together in a cage. Before they can free them, two dragons appear. In the ensuing fight, Sam is able to kill one with the sword, but the other escapes. He meets up with another dragon who has also captured a half dozen virgin women. They take one and use an incantation to open a door to Purgatory. They throw the woman in, and she rises from the fire, giving form to Mother.

Appearances

 * Season 6
 * Like A Virgin
 * Mommy Dearest  (Mentioned only)
 * Season 8
 * As Time Goes By  (Mentioned only)
 * Pac-Man Fever  (Mentioned only)
 * Season 9
 * Rock and a Hard Place  (Mentioned only)

Lore
Dragons are mythical creatures that usually take the form of a winged reptilian creature, often with the ability to breath fire. They appear in a variety of forms in cultures around the world. The Dragon featured in Supernatural relates to European traditions, where the typical dragon protects a cavern or castle filled with gold and treasure. Tales often feature a great hero who tries to slay the dragon and often rescue a princess or maiden the dragon has captured (or who has been offered to the dragon as a sacrifice).

In the New Testament, the Devil takes the form of a red dragon with seven heads and ten horns, in his battle against Archangel Michael.

Trivia

 * They appeared, in the series, as monsters of the week in Season 6 episode Like a Virgin.
 * Dragon tears can be used in spells, such as time travel, something only The Men-of-Letters knew.
 * In Bobby Singer's Guide to Hunting, Dr. Visyak wrote that the dragon-killing swords were forged with the blood of Hypolyes, a dragon who willingly sacrificed his life to help Eve, who realized her dragons were so powerful that they could destroy the other children she created.
 * Their human forms  were to be explained in a deleted scene in which one of the dragons was to say "Your army was defeated and your kingdom burned to the ground. Who are you going to tell your king did it? Me a man, or a sixty foot, fire-breathing serpent snake from Hell?"