One Elizabeth Montgomery she was the only cast to be in all of the shows.
Elizabeth Montgomery played both Samantha and Serena.
Serena, she first appeared in season two and was played by Elizabeth Montgomery as well as Samantha.
Tabitha
Samantha's identical cousin was Serena, played by Elizabeth Montgomery, who also played Samantha. When playing Serena, the blond Montgomery would wear a dark wig. Note that Montgomery was credited as "Pandora Spocks" when playing Serena.
12