This was filmed during the sixth month of Elizabeth Montgomery's real life pregnancy.
Although, in this episode, Endora insists that Samantha leave with her to avoid the hurtful portrayal of witches on Halloween, in Twitch or Treat (1966), Endora creates a house across the street from Samantha and Darrin so she can hold a Halloween party there, something Samantha says she holds every year.
When Endora turns herself into a little girl, the role is played by nine-year-old Maureen McCormick, who, four years later, went on to play Marcia Brady , the oldest sister on "The Brady Bunch".
This episode takes place on October 31, 1965.