Alcyoneus, in Greek mythology, was
(1) a giant, tall as a mountain, who inhabited the Isthmus of Corinth, and robbed and murdered all passers-by. He lived on herds, and lay in wait for Hercules, who travelled across the isthmus with large numbers of oxen, and with a huge rock he destroyed at one time twelve wagons and twenty- four men belonging to Hercules. When he was in the act of throwing a stone at Hercules, the latter slew him with the club he carried.
(2.) A dragon-footed giant, the son of Gaea (Earth), born from the blood of the emasculated Uranus. Of all his brothers he was the most powerful born at Pallene, where he lived, and whence lie drove the herds of oxen belonging to the god of the sun. Hercules made a search for the monster, and killed him by his superhuman strength. But no sooner had he been slain than he received new strength from his mother, the Earth, and began a renewed combat with Hercules. Minerva then instructed Hercules to drag him from Pallene; and when he was no longer in his own home, his strength failed him, and he died. He had seven beautiful daughters, the Alcyonides, named, respectively, Anthe, Alcippe, Asteria, Drimo, Methone, Pallene, and Phthonia. According to some, they all threw themselves into the sea upon the death of their father, and were transformed. into ice-birds by the sympathizing gods.