But Earth, vexed on account of the Titans
, brought forth the giants, whom she had by Sky. These were matchless in the bulk of their bodies and invincible in their might; terrible of aspect did they appear, with long locks drooping from their head and chin, and with the scales of dragons for feet. They were born, as some say, in Phlegrae, but according to others in Pallene. And they darted rocks and burning oaks at the sky. Surpassing all the rest were Porphyrion and Alcyoneus, who was even immortal so long as he fought in the land of his birth. He also drove away the cows of the Sun from Erythia. Now the gods had an oracle that none of the giants could perish at the hand of gods, but that with the help of a mortal they would be made an end of. Learning of this, Earth sought for a simple to prevent the giants from being destroyed even by a mortal. But Zeus forbade the Dawn and the Moon and the Sun to shine, and then, before anybody else could get it, he culled the simple himself, and by means of Athena summoned Hercules to his help. Hercules first shot Alcyoneus with an arrow, but when the giant fell on the ground he somewhat revived. However, at Athena's advice Hercules dragged him outside Pallene, and so the giant died.
[1.6.2] But in the battle Porphyrion attacked Hercules and Hera. Nevertheless Zeus inspired him with lust for Hera, and when he tore her robes and would have forced her, she called for help, and Zeus smote him with a thunderbolt, and Hercules shot him dead with an arrow. As for the other giants, Ephialtes was shot by Apollo with an arrow in his left eye and by Hercules in his right; Eurytus was killed by Dionysus with a thyrsus, and Clytius by Hecate with torches, and Mimas by Hephaestus with missiles of red-hot metal. Enceladus fled, but Athena threw on him in his flight the island of Sicily; and she flayed Pallas and used his skin to shield her own body in the fight. Polybotes was chased through the sea by Poseidon and came to Cos; and Poseidon, breaking off that piece of the island which is called Nisyrum, threw it on him. And Hermes, wearing the helmet of Hades, slew Hippolytus in the fight, and Artemis slew Gration. And the Fates, fighting with brazer clubs, killed Agrius and Thoas. The other giants Zeus smote and destroyed with thunderbolts and all of them Hercules shot with arrows as they were dying.
Source: Classical E-Text: Apollodorus, The Library 1
Alternate Names of Characters Involved in the Gigantomachy