Hercules’ fourth labour—by some counts, for there is no single definitive telling—was to capture the Boar. On the way there, Hercules visited Pholus (“caveman”), a kind and hospitable centaur and old friend. Hercules ate with him in his cavern—though the centaur devoured his meat raw—and asked for wine. Pholus had only one jar of wine, a gift from Dionysus to all the centaurs on Mt. Erymanthos. Hercules convinced him to open it, and the smell attracted the other centaurs. They did not understand that wine needs to be tempered with water, became drunk, and attacked. Hercules shot at them with his poisonous arrows, and the centaurs retreated all the way to Chiron’s cave.
Pholus was curious why the arrows caused so much death, and picked one up but dropped it, and the arrow stabbed his foot, poisoning him. One version states that a stray arrow hit Chiron as well, but Chiron was immortal, although he still felt the pain. Chiron’s pain was so great, he volunteered to give up his immortality, and take the place of Prometheus, who had been chained in to the top of a mountain to have his liver eaten daily by an eagle, although he was an immortal Titan. Prometheus’ torturer, the eagle, continued its torture on Chiron, so Hercules shot it dead with an arrow. It is generally accepted that the tale was meant to show Hercules as being the recipient of Chiron’s surrendered immortality. However, this tale contradicts the fact that Chiron later taught Achilles. The tale of the Centaurs sometimes appears in other parts of the twelve labours, as does the freeing of Prometheus.
Hercules had visited Chiron to gain advice on how to catch the boar, and Chiron had told him to drive it into thick snow, which sets this Labour in mid-winter. Having successfully caught the Boar, Hercules bound it and carried it back to Eurystheus, who was frightened of it and ducked down in his half-buried storage pithos, begging Heracles to get rid of the beast, a favorite subject for the vase-painters. Heracles obliged. Roger Lancelyn Green states in his Tales of the Greek Heroes that Hercules threw it in the sea. It then swam to Italy, where its tusks were preserved in the Temple of Apollo at Cumae. Three days later, Eurystheus, still trembling with fear, sent Hercules to clean the Augean stables.