From Oxygen Dream Dictionary:
Dragon:
Animal instincts to be conquered, hence the battles of Saint George and Saint Michael with 'the dragon." The dragon fight is related to the archetypal themes of search/quest, the hero/heroine, and, in more modern terms, separating ourselves from the collective values of our parents/ancestors. The dragon can symbolize a guardian or guarding quality; something that needs to be guarded/protected in your life/psyche. As a devouring creature, it may represent negative aspects of the mother archetype. It shares much of the same symbolism as the snake, and both can symbolize the developing Self
Pagan/Wiccan Interpretation of Dragon {Positive}
(Source: Myths - Dreams - Symbols)
Related pages: 9, with 20:2).
Satan's earthly proxy - the beast from the sea - also has seven heads and ten horns, and he is scarlet in color as well (13:1; 17:3). Satan's character is mirrored in his earthly representatives. The dragon personifies evil. Since ancient mythology had many references to dragons, John's audience would have understood that the dragon of Revelation 13 represented a cosmic enemy.
Exactly what the dragon's seven heads represent is not immediately clear. However, given John's use of seven as a numerical symbol of completeness, perhaps this suggests the universal nature of Satan's power and that he completely embodies within himself all evil. The dragon also has seven diadems or royal crowns on his heads. They could represent Satan's spurious claim against Christ. As the Lord of Lords, it is to Jesus that all crowns of authority belong. He is the one who will be crowned with many diadems (19:12, 16).
We are told the dragon had 'swept a third of the stars out of the sky and flung them to earth" (12:4). This fraction is used several times in Revelation. Perhaps we should interpret it as meaning a significant minority.
Links: Dragons and the Earth Spirit The Serpent's Prayer: The Psychology of an Image ">Dream Symbols, Dream Interpretation, Dream Symbol Dragons, Dream Dictionary Dragons, Meaning of dreams about Dragons, Dream Interpretation Dragons, Dream Analysis Dragons, Dreaming of Dragons