This paper analyzes the female monster and the ideology of motherhood in human-alien hybrid SF-Horror films from the perspective of the female spectator. First, this paper examines the hybrid style of SF-Horror film, Invasion of the Body Snatcher which deals with cloning. Second, it traces the genealogy of human-alien hybrids in SF-Horror films, comparing the male-alien hybrid and the female-alien hybrid. The male-alien hybrid in movies such as District 9, Venom, is either castrated or is treated as a hero. The female-alien hybrid in films such as Alien and Splices, is monstrous agent of castration and reproduction. Third, the paper analyzes Parasyte, a unique film in the genealogy of human-alien hybrid films, which emphasizes the ideology of motherhood in patriarchal hierarchy. Parasyte visualizes the threat and horror deriving from human and alien hybrid through striking imagery. It is possible, however, that a female-position spectator can not enjoy Parasyte in spite of its striking visual effects because of its undercurrent patriarchal human-centered ideology. Such ideology incurs uneasiness in certain female spectators. But as Mancia Diawara and Bell Hooks assert, such spectator uneasiness can create the rupture in the system. using ’oppositional gaze’ and ’resistant spectatorship’ as strategies of resistance.