In Greek mythology, the hero Achilles is known for his near invincibility, particularly evident in the Trojan War. His mother, Thetis, dipped him in the River Styx to grant him protection, leaving only his heel vulnerable. This singular weakness became globally recognized as the "Achilles heel," symbolizing that even the strongest individuals have their limited vulnerabilities. Achilles represents the themes of glory, fate, and the tragic nature of heroism, illustrating how greatness often comes at a significant personal cost.