Aka : Mephistopheles, Miphostophiles, Mephisto, Mephostophiles and Mephistophilis 

Element/sin : Mercury or Jupiter 

Shape : A dragon;  a young nobleman in a red doublet trimmed with gold, with a stiff silk cloak, a cock's feather in his hat, wearing at his side a long sword; an elderly Gray Friar. 

Origin : The great Abbot Trithemius referred to Faust in a letter dated 1507, calling the magician a fraud and a mountebank who should be whipped. 

Myths :  served as familiar demon to the German wandering scholar and magician Georgius Sabillicus Faustus (1480-1542) as part of Faust's pact with the Devil. Faust was a great scholar who grows tired of the vanity and impotence of ordinary human knowledge. He decides to turn to magic to fulfill his lust for fame, wealth and power. 

Source:

Volsbuch vom Doktor Faustus (1587)

Christopher Marlowe  The Tragical History of the Life and Death of Dr. Faustus (1589)

Goethe  Faust (1775)

Thomas Man Doctor Faustus  (1947)

Butler Ritual Magic

Quote :

May the gods of Acheron be propitious to me. Away with the three-fold godhead of Jehovah. Welcome, spirits of fire, air, water, and earth. We ask your favor, O prince of the East, Belzebub, monarch of burning hell, and Demogorgon, that Mephostophilis may appear and rise. What dost thou delay? By Jehovah, Gehenna, and the holy water which I now sprinkle, and the sign of the cross which I now make, and by our vows, may Mephostophilis himself now rise, commanded by us. Marlowe

This hellish Grand-Duke Mephistoph. appeared to me, Faust, first at a cross-road, and in a very cruel guise, like a bear, then mannerly like a lion; but through much persistence in my conjurations I managed to get him to promise to come to my study, and he came in the form of an old grey man. This spirit immediately made a pact with me for twenty-four years, and promised to bring me quick as thought to any place. Also I was to learn from him all the secret arts of nigromancy, and he promised to teach me magic properly. He also said: 'All secret arts of nature lie hidden in me. I govern in the hour of Jupiter; therefore I am very much attached to man, and warn him against making pacts. But if he will not heed my warning, then he will find no mercy from me when his hour strikes; nor would the star of Lucifer my Principal which is called Cerumepihiton and hardens the heart of men, allow it. I am most friendly when I appear as a grey man.' Karl Kohl Doctoris Iohannis Fausti magiae naturalis et innatural