"The marine's sister" (Tracy Ashton) is sister to the Phantom, or the incarnation of him that toured with a Polish circus. She has only one leg, and a "car stick" in the place of the other. According to Sue, she killed three kids in the first grade.
She appears in Nikki's house in the end credits. She first appears alone in the dark, looking around. She says, "Sweet." She is then joined by others.