The Facehugger (from Alien) and the Headcrab (from Half-Life) are very similar in that they want to couple with your head/face area, but they do so for different reasons:
The Facehugger locks around your mouth for the alien implantation process. The Facehugger inserts a tube-like proboscis into the mouth and down the throat of the host, supplying the host with oxygen while implanting an embryo (which will exit you as a Chestburster).
The Headcrab couples with its hosts head in an attempt to control the host’s nervous system. Upon sighting a humanoid host, a headcrab will leap for the victim’s face and affix itself to the cranium, whereupon they will use their beak to break into the victim’s skull. The Headcrab then proceeds to take over its host’s motor functions through some unknown biological process. The host will then undergo physical changes, presumably induced through chemical means – the host basically becomes a zombie.
Would you rather contend with a Facehugger or a Headcrab? I choose Headcrab since they can be domesticated.
✘ Hack It! ✘