In Greek mythology , one of the Centaurs .
The son of Cronus and the sea nymph Philyra, he lived at the foot of Mount Pelion in Thessaly and was renowned for his wisdom and his knowledge of medicine. He was the teacher of many Greek heroes, including Achilles , Heracles , Jason , and Asclepius . Wounded accidentally by a poisoned arrow shot by Heracles, he was in such agony that he surrendered his immortality in order to die. Zeus placed him among the stars as the constellation Sagittarius .