An enormous monster once trapped by the gods under a mountain. Human-shaped with mottled green skin, human hands, the talons of an eagle and scaly, reptilian legs. Once released, Typhon caused swathes of devastation.
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Typhon is the final son of Gaia, fathered by Tartarus, and is themost deadlymonster of Greek mythology. Typhon was known as the "Father of all monsters"; his wife Echidna was likewise the "Mother of All Monsters."
Typhon was described in pseudo-Apollodorus, Bibliotheke,as one of the largest and most fearsome of all creatures. His human upper half reached as high as the stars. His hands reached east and west and had a hundred dragon heads on each. He was feared even by the mighty gods. His bottom half was gigantic viper coils that could reach the top of his head when stretched out and made a hissing noise. His whole body was covered in wings, and fire flashed from his eyes.
Typhon attempts to destroy Zeus at the will of Gaia, because Zeus had imprisoned the Titans and defeated the Gigantes. Typhon initially overcome Zeus in their first battle, and tore out Zeus' sinews. However, Hermes recovered the sinews and restored them to Zeus. Typhon finally defeated by Zeus, who trapped him underneath Mount Etna.
Source(s): Percy Jackson and the Olympians - The Ultimate Guide ;;Wikipedia