Castor is a seventeen-year-old bobcat; 6' and 165 lbs., he has the standard Felid abilities. His skills include martial arts, brawling, knife fighting, and unarmed combat.

Background: Joseph Guillamo, with his twin brother Pietro, was bounced through foster homes since the age of 3. He developed a strange sense of humor as a defense mechanism, and learned to rely totally on his brother. The pair make a superb fighting team. By the time they were discovered by China and brought to Sanctuary, they'd already taken on the code-names of Castor and Pollux.