In Half-Life, what is the name of the alien that attaches to heads?

The story behind the answer

Headcrab is correct because, in Half-Life, these small, crab-like aliens leap onto a victim’s head and clamp down, taking control of the host’s nervous system and creating the series’ iconic “zombies.” The name is literal—crab on your head—making it easy to remember. By contrast, Bullsquids spit acid and Vortigaunts are intelligent aliens who later become allies. “Facehugger” is from the Alien film franchise, not Half-Life.

Introduced by Valve in 1998, headcrabs became a hallmark enemy, with variations in later games (fast and poison headcrabs in Half-Life 2). Memory tip: Think “H” for Half-Life and “Head”—the parasite’s target—plus “crab” for its shape and scuttling movement.