Typhon was the deadliest monster of Greek mythology. The last son of Gaia, fathered by Tartarus, he was known as the "Father of All Monsters"; his wife Echidna was likewise the "Mother of All Monsters." As the largest and most fearsome of all creatures, his prowess exceeded that of even the Titans and was enough to be regarded as the deadliest threat to Olympus, and was one of the few beings in existence whom Zeus openly feared.
His true form is always accompanied by a massive and devestating storm, obscuring his body and making it difficult to see. However, it is said that his human upper half reached as high as the stars, and his hands reached east and west. Instead of a human head, a hundred dragon heads erupted from his neck and shoulders; some, however, depict him as having a human head, with the dragon heads replacing the fingers on his hands. His bottom half consisted of gigantic viper coils that could reach the top of his head when stretched out and constantly made a hissing noise. His whole body was covered in wings, and fire flashed from his eyes, striking fear even into the Olympians.
During his first encounter with the Olympian deities, many of them fled in terror from the monster, with only Zeus remaining. Typhon attempts to destroy Zeus at the will of Gaia, because Zeus had imprisoned the Titans. Typhon overcomes Zeus in their first battle, and tears out Zeus' sinews. However, Hermes recovers the sinews and restores them to Zeus. Resuming the fight, the battle between Typhon and Zeus shook the very Earth to its core. Mountains were reduced to rubble, oceans boiled and dried up, and the sky was set ablaze. The battle was so intense that even the Underworld shook from the immensity of the power that was being exhanged between the two godly beings. After a long and hard-pressed fight,Typhon is finally defeated by Zeus, who traps him underneath Mount Etna by literally throwing the mountain ontop of him.
Typhon, however, is not so easily bested. It is said that his release will mark the end of the Olympian gods, and thus trigger the Second Titanomachy. His prison weakens with each passing century or so, evidenced by the erupting volcano he is imprisoned beneath from his sheer raw power alone.