Castor is the elder twin brother of Polydeuces, and together they are called the Dioscuri or the Hero Twins. Both Castor and Polydeuces have the same mother, Leda, but have different fathers. Castor's father is a mortal man named Tyndareus, while Polydeuces's father was the god Zeus, hence making Polydeuces immortal, while Castor is a mortal. During Castor's death, Polydeuces asked his father Zeus to share his immortality to Castor, and they were transformed into the Gemini constellation. His name means "beaver".
Design
Castor's design has some elements of Polydeuces' design, mainly its long, flowing blond hair. Castor has its chest area impaled by a tip of a spear, with its face resembles that of a skull. Castor is also riding a hobby horse, reminiscent of that of an undead horseman.
A hero in Greek mythology. He is Polydeuces's half-brother, but doesn't share his brother's immortality. He was struck and killed by an arrow, after which he and his brother became stars in the constellation Gemini.