Creatures part human and part horse.
The centaurs were descendants of Centaurus, a son of the music god Apollo. Most centaurs were governed by the bestial half of their double nature. Their behavior was uncouth, and a very small amount of wine drove them wild. When Heracles was entertained by Pholus, one of the few civilized centaurs, he made the mistake of demanding the guest's prerogative of a beaker of wine. Pholus could not refuse, though he hesitated before unearthing a jug of the liquid which he kept buried underground for fear of just the sort of consequence which now ensued.