Porphyrion
The King of the Giants who was destroyed by Zeus and Hercules together
Porphyrion started the first war between the gods and the Giants by kidnapping Hera after being shot with an arrow of Cupid. This, of course, made him fall in love with the Queen of the Olympians, so he started the war to keep Hera and to avenge the Titans. Led by Alcyoneus and the king, Porphyrion, the Giants attacked Olympus.
Warned by the Fates that the Olympians could not defeat the Giants without the help of a lion-skinned-mortal, Zeus decided that this must mean his son, Hercules, and sent Athena to find him.
Hercules defeated Alcyoneus after injuring him in the Giant's homeland, Pallene (where Alcyoneus was immortal) and then killed him outside of Pallene's borders. Porphyrion later dueled both Zeus and Hercules, but the combination of both god and demigod working together destroyed him, as only a god and demigod working together can defeat a Giant.
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