Mephisto is a character in German folklore and literature, often depicted as a cunning and malevolent demon who tempts individuals into making deals with him in exchange for their souls. He is most famously known for his role in Johann Wolfgang von Goethe's play "Faust," where he serves as the antagonist who leads the protagonist, Faust, astray. Mephisto is often portrayed as a symbol of temptation, corruption, and the darker aspects of human nature.