Castor and Polydeuces in Jason and the Golden Fleece
These twin Spartan brothers are the sons of Zeus and Leda, a lovely young lady whom Zeus seduced in the form of a swan. It's said that the brothers were later born from the eggs that Leda laid a while after. Some say that both brothers were immortal, while others say that only Polydeuces was. In the tale of the Golden Fleece, Polydeuces earns his keep by out-boxing the heavy weight champ, King Amycus. Castor and Polydeuces also pop up in the story of Theseus's later years, when they rescue their sister Helen, after Theseus kidnaps her. Polydeuces' Roman name is Pollux, but for some reason Castor is always Castor. It's said that upon their deaths the twins were turned into the constellation Gemini, and carried on their sailing spirit as nautical deities.