Greek mythology can never be complete without the mention of Achilles, the hero of the Trojan war, who was the son of the Nereid (sea nymph) Thetis and the mortal King Peleus, the head of the Myrmidons, which made him a demigod. The legend goes that when Achilles was an infant, his mother, Thetis, dipped him in the river Styx to make him immortal.