Alien Resurrection, the fourth and final installment of the Alien franchise, illustrates updated discourses about monster. While the first three installments of the franchise tended to focus on the surface horror caused by the monstrous appearance and enormous power of the Aliens, the final one explores the structural horror that the alien monster embodies. Re-examining the definition of monster, the essay investigates how the notion of monster and the feminine are associated and how the feminine monster can serve to challenge the patriarchal social system based on heterosexual normativity. Also, the essay points out how the film produces horror in presenting the cross-species monsters and the non-heterosexual relationship. The protagonist Ripley, who returns as a monster in Alien Resurrection after killing herself to eradicate the Alien queen in her body in the third installment, represents the claim that the monster is a cultural construct by ideological normativity, and at the same time, it can be a threat to that normativity. Alien Resurrection argues that horror in horror films is not from the monster per se, but what makes the monster-that is, the violence of normativity.