Hehe. The Protestants like to stretch that one a lot. ;) But good points. Just wanna clarify, Satan was an angel. He was created to shine a radiant light around God's throne, but he became egotistical and decided to try to take over heaven, and of course, was effortlessly defeated and cast down to earth where he would wait until his ultimate punishment. Here, he has been known to possess several forms, including the first being a serpent in the Garden of Eden. For its cooperation with Satan, the serpent was cursed and lost its legs so that it would be forced to slither in shame.
Satan himself, however, known very often for appearing as an incredibly beautiful and brilliant being, because that is what he was created as, despite the stereotypes of a horrendous-looking monster (which, of course, he has been known to shift to.)