The "facehugger" is a creature that as created by the artist H.R. Giger in the "Alien" movies. Facehuggers typically lie dormant in eggs until they sense
the movement of a possible host, at which point they hatch. They attack by attaching themselves to a host's face and implanting them with an alien
parasite, using a tube which is inserted into the host's mouth. This process varies in length from about
15 minutes to a few hours. After they have implanted the embryo, they detach from their host and die. The alien embryo then grows inside the host's ribcage and bursts out of them after a period of a few days, although this timeframe may vary.