Polyphemos (or Polyphemus) is a Kyklops in Greek mythology. He is the son of the god Poseidon and Thoosa. Polyphemos is a creature of strength and immense stupidity who broke the cardinal rule of hospitality in Ancient Greece. He lived in a cave on an island, and he had sheep. On the island also lived several other Kyklopes.
Polyphemos appears in Homer's Odyssey. On his journey home to Ithaca after the Trojan War, Odysseus lands on the island of Polyphemos. They come to the cave where Polyphemos lives. Polyphemos comes back and he traps them in his cave placing a boulder in front of the entrance, also eating some of Odysseus' men. Odysseus then thinks of a plan to get away. He tells Polyphemos that his name is "Nobody", and gives him wine to drink. When he is sleeping, Odysseus and his men take a log from the fire and shape the end of it to a point and drive it into the Kyklops', Polyphemos, only eye, so he could not see them anymore. In agony he cries out to the other Kyklopes for help. When they ask what has happened, he says that No man hurt him, so the Kyklopes leave him. The next morning Polyphemos lets his sheep out of the cave, but touches their backs so no one of the men could ride out on them. But Odysseus and his men hold themselves on the underside of the sheep, and so they get out. When Polyphemos realizes that Odysseus got away, he cries out to the other Kyklopes again. They asked him what happened, and he said "No man hurt me.", and so the other Kyklopes went away again. When Odysseus was on his ship again, he called out in rage to Polyphemos saying that he, Odysseus was the one who had destroyed his eye. As Odysseus went away he mocked Polyphemos. This is hubris. Polyphemos was very angry and threw a rock at them, but it missed the ship. Then he pled with his father, Poseidon, for revenge that all of Odysseus' men should die and that Odysseus should only come home to Ithaca after ten years. All of it comes true, as is told in the Odyssey.