In Norse mythology, Tialfi was the son of Egil and a champion runner. He became a slave to Tor, the god of thunder, after eating one of his goats. On a journey with Tor, Tialfi stopped to run a race against the young giant Hugi. The giant was an illusion and the embodiment of thought; and since no one can run faster than thought, Tialfi lost. In the legend of Tor’s duel with the giant Hrungnir, Tialfi becomes squire to Tor when he kills Hrungnir’s squire, Mist Calf.