Who is Zeus' worst enemy?

In Greek mythology, Zeus's worst enemy is generally considered to be Typhon, also spelled Typhoeus, a monstrous serpentine giant who challenged Zeus for supremacy of the cosmos and nearly defeated him. Typhon was the most fearsome monster in Greek mythology, described as taller than mountains, with a hundred dragon heads, eyes that breathed fire, and a voice that was both terrifying and divine, born from Gaia and Tartarus to avenge the Titans. According to Hesiod's Theogony and Apollodorus, Typhon attacked Olympus after Zeus imprisoned the Titans, and in their first battle, Typhon actually defeated Zeus, ripping out his sinews and leaving him helpless, until Hermes and Pan recovered them and Zeus renewed the fight, finally defeating Typhon with thunderbolts and burying him under Mount Etna, where his fiery breath causes volcanic eruptions. Other major enemies of Zeus include the Titans led by Cronus his father, whom Zeus overthrew in the Titanomachy, and the Giants in the Gigantomachy who tried to storm Olympus. Among mortals and gods, Zeus also had recurring conflicts with his wife Hera and with Prometheus who defied him. However, Typhon is universally described as Zeus's greatest and most dangerous foe, the only being who nearly overthrew him and ended Olympian rule, making him Zeus's worst enemy in terms of sheer power and threat to cosmic order, representing chaos against Zeus's order.