The hero notorious for his tragic flaw is Achilles from Greek mythology. His primary flaw, or hamartia, is his overwhelming pride, as evidenced by his refusal to participate in the Trojan War after a dispute with Agamemnon. This decision ultimately leads to significant consequences for both him and his comrades, illustrating how a singular character flaw can lead to one's downfall. Achilles' story highlights the theme of heroism intertwined with personal failure, showcasing the complexity of mythological figures who reflect human imperfections.