Fast Zombie

The Fast Zombie is the result of a human host under the control of a Fast Headcrab. As the name implies, Fast Zombies are extremely agile, and can be quite intimidating when faced in large numbers.

Appearance & Capabilities
Fast Zombies are much leaner than other zombie variants, stripped of their outer skin, some body tissue, and most or all organs (revealing large parts of its skeleton). It is unclear how or why this decomposition takes place so consistently. Fast Zombies also have longer claws than other zombies.

What distinguishes the Fast Zombie from other zombies is its ability to climb and move quickly, thus being able to confuse and surprise its prey. Fast Zombies also make loud wails while attacking and can be heard babbling while idle. Fast Zombies stand on two legs while slashing with its claws or standing up, but move on all four legs while running or climbing.

Like Standard Zombies, Fast Zombie torsos can survive when separated from the legs. The only difference is that Fast Zombie torsos crawl and attack faster.

In Episode Two, in the chapter Riding Shotgun, a Fast Zombie at one point succeeds in latching onto the hood of the player's Muscle Car while the car is moving. (Alyx kicks it off shortly after its initial latch-on).

Fast Zombies, if needed, will lunge at its target to close any distance quickly, and will slash the target upon coming into contact. The attack does the same amount of damage as the normal slash attack.

Tactics
Fast Zombies, although they can be very frightening, aren't particularly dangerous on their own because their attacks are fairly weak. Unfortunately, they - more often than not - travel in "packs" of three to four. They're also not particularly hardy - they're difficult to hit due to their fast and generally unpredictable movement. If facing a Fast Zombie, use the shotgun and aim for the head.

On the rooftops of Ravenholm in Half-Life 2, the biggest threat is actually falling off by surprise when a Fast Zombie suddenly attacks, thus causing fall damage while the zombie pursues.

During "We don't go to Ravenholm..." and the rooftop battles with the fast zombies, they constantly climb up building's gutters. While doing so, the player will hear a rattling beat, and the gutter will move side-to-side. However, the enemy below might not be a fast zombie, due to the fact that if any kind of zombie/headcrab touches the pipe, it makes the same noise. After Grigori throws Gordon the shotgun, grab it and look for the gutters that are rattling at the edges of the rooftop. Aim over the side of the building and shoot the zombie before it reaches the top. Doing this will save some time before more fast zombies become overwhelming. The magnum also works well if or when shotgun shells have ran out, although there are plenty of ammo caches for the shotgun throughout the town.

When a fast zombie is approaching, try to use the environment as an advantage. Quickly hide behind cover and stay close to the edge and wait for the zombie to come around the corner. Fire the shotgun at it as soon as it is in range. Shoot the zombie as it leaps, instantly killing it in mid air. It's recommended to use the magnum for this, however, because the shotgun has a slightly lower precision. Hiding behind cover will prevent the fast zombie from using its leap attack that most players fall victim to due to the surprise and disorientation it causes. This tactic will work with most other enemies, except for, of course, the ones that throw or, in the Zombine's case, hold grenades.

Fast Zombies can be detected by the distinct howling they tend to emit, though at closer ranges they can be found by still other noises; growls, babbling, and screams.

In Episode Two, Fast Zombies sometimes pretend to be dead, then jump up to attack when approached. This tactic was also used by Standard Zombies in Half-Life 2. When investigating an area littered with zombie corpses, check if any still have headcrabs attached to their head, as this is a good sign the zombie is merely playing dead. If so, shoot them in the head just in case. It pays to be sure.

Fast Zombies also tend to hide behind large objects. There is no real way to counter this. Simply stay alert, and be ready to fire when the zombie reveals itself. They also like to lurk in dark areas, so be alert.

Behind the scenes

 * The Fast Zombie was made from the Combine Assassin and the Alien Assassin.
 * It originally had trousers and socks, while its skin was greenish.

Trivia

 * It has been theorised by some players that the Fast Zombie strips its own flesh off after possession, rather it being due to some accelerated form of decomposition. According to this theory, the host is dead, so the howls and incoherent babbling could be due to the headcrab having total control of the host body, and so makes fast headcrab vocalisations with the voicebox of the host.
 * Despite the mutilation of the body and absence of some muscle tissue, a Fast Zombie is still able to jump great distances and move very quickly.
 * The scream emitted by the Fast Zombie while executing its leaping attack appears to be a sped-up version of an extremely common stock sound effect, the Howie Scream, which has been used in many movies and TV shows. The Poison Heacrab second scream, , appears to be a sped-up version of.
 * Removing a Fast Zombie's headcrab reveals that the host has an uncovered skull with no skin.
 * Starting in Half-Life 2: Episode One, Fast Zombies torsos can be cheat spawned using the code "npc_fastzombie_torso". Spawning a torso near Alyx Vance, it will climb on Alyx's legs and up to her face.
 * The growling noise a Fast Zombie makes when it attacks is actually a sped up Poison Zombie moan.
 * In Episode One, Fast Zombie torsos crawl while holding their bodies slightly upright. In Episode Two, the torsos hold their body a little lower, which makes them crawl faster.
 * The inspiration of the fast zombie's anatomy is from the Alien Assassin zombie form.

List of appearances

 * Half-Life 2
 * Half-Life 2: Raising the Bar
 * Half-Life 2: Episode One
 * Half-Life 2: Episode Two