Headcrab Zombie

Headcrab Zombies are creatures that are created when a headcrab attaches itself to the head of a human.

Infection
Once a headcrab gets a firm grip on a victim's head, it will infect and take over the new host's nervous system, turning it into a headcrab zombie. The type of headcrab determines the type of zombie, each having different abilities.

Standard Zombie
The standard zombies use elongated claws to strike at their victim, their halfway-rotting corpse is split open and is proven to be a mouth as it was shown to be revealed within the Black Mesa Research Facility.

Poison Zombie
Poison zombies are the strongest of all zombies. They can carry up to four other poison headcrabs on their back, which they throw at potential hosts. They can withstand many gunshots, however, they are very slow.

Fast Zombie
To increase their speed and mobility, fast zombies have done away with their skin and organs. They are very fast, bounding on all fours to their target, and can easily jump 2 meters (6 and a half feet). With these abilities, they are obviously more deadly then the ordinary zombies. This is an example of a headcrab that has more control over the host.

Zombine
A Combine soldier whose biological weapon backfired and took over the host body, they are capable of short sprints, yet have no elongated claws. It is not unheard of for them to equip a grenade, although in their zombified state, they know not of the danger but are still familiar with its use. Because of this, they kamikaze. These are not natural zombies, and none are seen as such, as headcrabs are taken from another Xen where they usually feast on Vortigaunts, Chumtoads, or anything else from their natural realm. They can be murmuring through their vocoders lines such as "sector is... (deep breath) not secure" or "necrotics... inbound", suggesting that they are aware of their status as zombies, and may also be why they kamikaze, attacking potential threats such as Resistance members and themselves.

Gonome
The Gonome is the evolved form of the standard zombie. It can toss gobs of explosive slime at its opponents, and has grown longer claws. It sits somewhere between normal and fast zombies in terms of speed.

Appearances

 * Half-Life (1998)
 * Half-Life 2 (2004)
 * Half-Life: Alyx (2020)