Theseus is famed for his cleverness in escaping from the Labyrinth, a complex maze designed by the architect Daedalus. He managed to navigate the maze and defeat the Minotaur with the help of a ball of thread given to him by Ariadne. After slaying the creature, Theseus successfully retraced his steps, demonstrating both his intellect and courage. This tale showcases themes of heroism, ingenuity, and the struggle against monstrous beings in Greek mythology.