Headcrab

A headcrab is a fictional alien parasitoid found in the Half-Life video game series created by Valve Software. They are the most common and arguably the most iconic aliens in the series.

Attributes

Depiction

Headcrabs are depicted as parasitic lifeforms roughly 2 feet (0.61 m) long. The common headcrab variant has rounded bodies with four legs for movement, two of which are long clawed legs at the front and two stubby legs at the back. Their pair of large frontal claws are for attacking, and as additional support when standing still. Under the headcrab's body is a large rounded mouth surrounded by mangled, rigid flesh with a sharp claw-like beak.

Physically, headcrabs are frail, a few bullets or a single strike from the player's melee weapon being sufficient to dispatch them. They are also relatively slow-moving and their attacks inflict very little damage. However, they can leap surprising distances and heights. Headcrabs seek out larger human hosts, which are converted into zombie-like mutants that attack any living thing they can find. The converted humans are far more resilient than an ordinary human would be and inherit the headcrab's resilience toward toxic and radioactive materials. Headcrabs and headcrab zombies die slowly when they catch fire. The games also establish that while headcrabs are parasites that prey on humans, they are also the prey of the creatures of their homeworld. Bullsquids, Vortigaunts, barnacles and antlions will all eat headcrabs and Vortigaunts can be seen cooking them on several occasions.