Regan Teresa MacNeil is a shy creative young woman who becomes possessed by the demon Pazuzu. Regan assumes a strange aggressive behavior that worries and scares her mother and begins to develop progressively inhuman traits and mannerisms. However at some point Regan grows to be an adult who leaves her mother's house and is able to control her demonic powers. The girl and Pazuzu develops a bond of father and daughter more than anything. If angry or in an state of self-defense Regan can unfold her demonic side to an awakened state; and it won't be pretty. Regan became an icon of horror films and a primary influence for subsequent films depicting demonic possession. The character has been spoofed in many parodies (in one occasion by Linda Blair herself) such as the Scary Movie series. She also resurrected Father Karras after him and Pazuzu came to an agreement after years of bloodshed and demonic possessions.