Polyphemus is the one-eyed giant son of Poseidon and Thoosa in Greek mythology, one of the Cyclopes described in Homer's Odyssey. His name means "abounding in songs and legends", "many-voiced" or "very famous". Polyphemus first appeared as a savage man-eating giant in the ninth book of the Odyssey. The satyr play of Euripides is dependent on this episode apart from one detail; Polyphemus is made a pederast in the play. Later Classical writers presented him in their poems as heterosexual and linked his name with the nymph Galatea. Often he was portrayed as unsuccessful in these, and as unaware of his disproportionate size and musical failings. In the work of even later authors, however, he is presented as both a successful lover and skilled musician. From the Renaissance on, art and literature reflect all of these interpretations of the giant.

Outis is an often used pseudonym that appeared famously in Classical Greek legends. Modern artists, writers, and others in public life have adopted the use of this pseudonym in order to hide their identity and it has been used for fictional characters as well.