In Greek mythology, Porphyrion (Ancient Greek: Πορφυρίων) was one of the Gigantes, earthborn children of Gaia (from the blood of castrated Uranus, or in some accounts of Gaia and Tartarus). Apollodorus ranks him with Alcyoneus as greatest of the Giants; Pindar calls him "king of the Giants." In the Gigantomachy he assaults Heracles and Hera and is slain by Zeus' thunderbolt and Heracles' arrow — or, in Pindar, by Apollo.
Adapted from Wikipedia, "Porphyrion" · CC BY-SA 4.0
I.In the Gigantomachy
According to Apollodorus, during the battle of Giants and Olympians Porphyrion attacked Heracles and Hera. Zeus filled him with lust for Hera; when he tried to assault her, Zeus struck him with a thunderbolt and Heracles finished him with an arrow. Pindar instead has Apollo's bow kill the Giant king. Aristophanes' Birds jokes that even a single Porphyrion gave Zeus enough trouble.
Later poets expand the threat: Claudian has him uproot Delos to hurl at the sky; Nonnus has Gaia promise him Hebe if the Giants subdue Dionysus.
II.In art
He is named on Archaic and Classical vases opposing Zeus, Heracles, and Athena, and was probably labelled on the Siphnian Treasury Gigantomachy at Delphi. On the Pergamon Altar frieze he appears in combat with Zeus — one of the best-known surviving images of the Giant king.