Not to discourage further questions, answers, discussions, revisions, dissents, et cetera, but there's an FAQ section just on dragons, in the Religion and mythology section. As well, you might want to put "dragon" in the search box at upper right (Web interface); there are some hits there that aren't in the FAQ, like a pointer to When did the first interpretations of dragons appear in literature or art? Were the Chinese or the English the first?, where /u/mdhs started with "Although I can't give you an explanation as to where they both come from, I can tell you that the two have little in common. Actually, if it wasn't for the translation of the Chinese "long" in English as "Dragon" it is unlikely there would be any connection at all.".