Pholus
Pholus was one of the few Centaurs who was friendly towards mortals. Pholus was a friend of Heracles.
Pholus lived in a cave at Mount Pholus, which was named after him; this mountain was in Arcadia. He had wine that would drive other Centaurs crazy with its sweet smell.
One day, Heracles came to visit, during his 4th Labour, which was to fetch the Erymanthian Boar. As his guest, Pholus opened his wine skin, but the smell of the wine drove many of the nearby Centaurs mad with desire to drink this wine. Among those who attacked Heracles was the Centaur Eurytion. They attacked Heracles, but the hero killed many Centaurs with his poisoned arrows. Heracles managed to drive the Centaurs away, and Eurytion was among those who escaped. Eurytion would later meet Heracles again.
Pholus accidentally dropped one of Heracles' arrows on his hoof, and was killed instantly. Heracles buried Pholus.
Pholus wasn't the only one poisoned by the hero's arrow. When Cheiron was helping Heracles, Heracles either accidentally shot him, or Cheiron dropped the arrow on his foot. However, Cheiron didn't die, being immortal, but he could not be cured. Later, Cheiron gave up his immortality so he could finally die. See Cheiron.
By Jimmy Joe