These are stories where humanity is invaded by alien parasites who take over their bodies and lives. (scifimoviepage.com)
Astrocreep — a deliciously dark humored little point and click horror adventure in which you control a small alien parasite who must kill the humans, evolve and infest an entire space station with your offspring. (freegameplanet.com)
God's love bursts out of your heart like some kind of vicious alien parasite. (religion.blogs.cnn.com)