Ancient myth believed that beneath mount etna a mighty giant was buried. who was believed to have hurled this giant from heaven?

 Zeus

In Greek mythology, the king of the gods, Zeus, defeated the powerful giant Typhon and hurled him down beneath Mount Etna.

Zeus was the sky and thunder god who ruled as the king of the gods in Greek religious legend.  Typhon was a great and monstrous creature said to be the offspring of Gaia, the earth goddess, and Tartarus, the deity of the deep abyss (also called Tartarus) -- which we might equate with the idea of hell.  [That account of Typhon's origins comes from the ancient Greek poet, Hesiod, who lived around 700 BC.]

The myth told of a great battle for supremacy over the universe between Zeus and Typhon, in which Zeus prevailed and cast Typhon down into an imprisonment underneath Mount Etna, which is located near the eastern coast of the island of Sicily.   Typhon was described by Hesiod as a "terrible, outrageous and lawless" being of incredible strength, who had a hundred snake heads protruding from his shoulders.  Another ancient Greek source described Typhon as a giant winged beast with a human upper body and snake coils as his lower body, and the most powerful of all offspring of Earth (Gaia).

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