The legend of St. George slaying a dragon is well known. Some people interpret the legend as St. George representing Christianity and the dragon as the pagan world. In the end, the good or the Christian world is triumphing over evil or the pagan world. Several elements of the legend of St. George resemble the story of the gargoyle of Rouen.
Whether the story is true or fictional, you have to ask for yourself what kind of animal has inspired the people of that time. If the story is fictional, why not have used an animal like a wolf to symbolize evil. What kind of scary reptile was behind the dragon's legend ?
The Golden Legend (Aurea Legenda)
Compiled by Jacobus de Voragine, 1275
Translated in english by William Caxton, 1483
Here followeth the Life of S. George Martyr.
"S. George was a knight and born in Cappadocia. On a time he came in to the province of Libya, to a city which is said Silene. And by this city was a stagne or a pond like a sea, wherein was a dragon which envenomed all the country. And on a time the people were assembled for to slay him, and when they saw him they fled. And when he came nigh the city he venomed the people with his breath, and therefore the people of the city gave to him every day two sheep for to feed him, because he should do no harm to the people, and when the sheep failed there was taken a man and a sheep. Then was an ordinance made in the town that there should be taken the children and young people of them of the town by lot, and every each one as it fell, were he gentle or poor, should be delivered when the lot fell on him or her. So it happed that many of them of the town were then delivered, insomuch that the lot fell upon the king's daughter, whereof the king was sorry, and said unto the people: For the love of the gods take gold and silver and all that I have, and let me have my daughter. They said: How sir! ye have made and ordained the law, and our children be now dead, and ye would do the contrary. Your daughter shall be given, or else we shall burn you and your house.
When the king saw he might no more do, he began to weep, and said to his daughter: Now shall I never see thine espousals. Then returned he to the people and demanded eight days' respite, and they granted it to him. And when the eight days were passed they came to him and said: Thou seest that the city perisheth: Then did the king do array his daughter like as she should be wedded, and embraced her, kissed her and gave her his benediction, and after, led her to the place where the dragon was.
When she was there S. George passed by, and when he saw the lady he demanded the lady what she made there and she said: Go ye your way fair young man, that ye perish not also. Then said he: Tell to me what have ye and why weep ye, and doubt ye of nothing. When she saw that he would know, she said to him how she was delivered to the dragon. Then said S. George: Fair daughter, doubt ye no thing hereof for I shall help thee in the name of Jesus Christ. She said: For God's sake, good knight, go your way, and abide not with me, for ye may not deliver me. Thus as they spake together the dragon appeared and came running to them, and S. George was upon his horse, and drew out his sword and garnished him with the sign of the cross, and rode hardily against the dragon which came towards him, and smote him with his spear and hurt him sore and threw him to the ground. And after said to the maid: Deliver to me your girdle, and bind it about the neck of the dragon and be not afeard. When she had done so the dragon followed her as it had been a meek beast and debonair. Then she led him into the city, and the people fled by mountains and valleys, and said: Alas! alas! we shall be all dead. Then S. George said to them: Ne doubt ye no thing, without more, believe ye in God, Jesus Christ, and do ye to be baptized and I shall slay the dragon. Then the king was baptized and all his people, and S. George slew the dragon and smote off his head, and commanded that he should be thrown in the fields, and they took four carts with oxen that drew him out of the city.
Then were there well fifteen thousand men baptized, without women and children, and the king did do make a church there of our Lady and of S. George, in the which yet sourdeth a fountain of living water, which healeth sick people that drink thereof. After this the king offered to S. George as much money as there might be numbered, but he refused all and commanded that it should be given to poor people for God's sake; and enjoined the king four things, that is, that he should have charge of the churches, and that he should honor the priests and hear their service diligently, and that he should have pity on the poor people, and after, kissed the king and departed."
The mysterious origin of the dragon (Page 2)