Mephistopheles (, German pronunciation: [mef?'sto:f?l?s]; also Mephistophilus, Mephostopheles, Mephistophilis, Mephisto, Mephastophilis, and other variants) is a demon featured in German folklore. He originally appeared in literature as the demon in the Faust legend, and he has since appeared in other works as a stock character (see: Mephistopheles in the arts and popular culture).
Traditional scholars of Germanic mythology commonly use the spelling "Mephistopholes," based on a transliteral understanding of the 15th century spelling of the character . The word may derive from the Hebrew (mêp?î?) which means "scatterer, disperser", and tophel, short for ? (t?p?el ?eqer) which means "plasterer of lies". The name can also be a combination of three Greek words? (m?) as a negation, (phs) meaning "light", and "philis" meaning "loving", making it mean "not-light-loving", possibly parodying the Latin "Lucifer" or "light-bearer".
The name Mephistopheles is associated with the Faust legend of an ambitious scholar, based on the historical Johann Georg Faust. In the legend, Faust makes a deal with the Devil at the price of his soul, Mephistopheles acting as the Devil's agent.
From the chapbooks, the name entered Faustian literature. Many authors have used it, from Christopher Marlowe to Goethe. In the 1616 edition of Marlowe's The Tragical History of Doctor Faustus, Mephostophiles became Mephistophilis.
Mephistopheles in later treatments of the Faust material frequently figures as a title character: in Meyer Lutz' Mephistopheles, or Faust and Marguerite (1855), Arrigo Boito's Mefistofele (1868), Klaus Mann's Mephisto, and Franz Liszt's Mephisto Waltzes. There are also many parallels with the character of Mephistopheles and the character Lord Henry Wotton in The Picture of Dorian Gray by Oscar Wilde. 
Although Mephistopheles appears to Faustus as a demon - a worker for Lucifer - critics claim that he does not search for men to corrupt, but comes to serve and ultimately collect the souls of those who are already damned. Farnham explains, "Nor does Mephistophiles first appear to Faustus as a devil who walks up and down on earth to tempt and corrupt any man encountered. He appears because he senses in Faustus' magical summons that Faustus is already corrupt, that indeed he is already 'in danger to be damned'."
Mephistopheles is already trapped in his own Hell by serving the Devil. He warns Faustus of the choice he is making by "selling his soul" to the devil: "Mephistophilis, an agent of Lucifer, appears and at first advises Faust not to forgo the promise of heaven to pursue his goals". Farnham adds to his theory, "...[Faustus] enters an ever-present private hell like that of Mephistophiles".
Shakespeare mentions "Mephistophilus" in the Merry Wives of Windsor (Act I, Scene I, line 128), and by the 17th century the name became independent of the Faust legend. According to Burton Russell, "That the name is a purely modern invention of uncertain origins makes it an elegant symbol of the modern Devil with his many novel and diverse forms".
Mephistopheles is also featured as the lead antagonist in Goethe's Faust, and in the unpublished scenarios for die Walpurgis-Nacht (German for "the Walpurgis-Night"), he and Satan appear as two separate characters.