Fast Headcrab

The Fast Headcrab is a sub-species of Headcrabs previously unknown before the Combine invasion. It is unknown whether they were native to Xen but never encountered before, a recent evolution, or whether they are the result of the genetic manipulation of a normal Headcrab by the Combine for use as biological weapons.

Appearances
The fast headcrab looks much slimmer and more agile than a normal headcrab, having thinner, almost spider-like legs. They also have slightly less bulky bodies and, surprisingly, do not have a "beak" like other headcrab variants are known to have. Fast headcrabs share many of the vocalisations of the standard headcrab. Examined up close, fast headcrabs have wart-like bumps on their skin in certain areas. The legs of a fast headcrab also have elongated claws, which as well as serving as weapons and a means to latch on to surfaces, waiting to attack unsuspecting prey. This is seen in Half-Life 2: Episode One, Lowlife. They drop off when the player gets too close or shines their flashlight on them. Fast headcrabs have been seen cooked and eaten by Vortigaunts which suggests that they are somewhat palatable as a food source. Fast headcrabs are more commonly seen eaten than standard headcrabs, which probably indicates they taste better than standard headcrabs.

Capabilities


The fast headcrab attacks in much the same way as a normal headcrab, and does about the same amount of damage. The main difference is that fast headcrabs close distance between themselves and their target very quickly before proceeding to leap at the target frantically. Their speed and unpredictable movement patterns make them difficult targets, and they can be very dangerous in groups of three or more.

Fast Zombie
Like all other headcrabs, fast headcrabs can latch onto a human's head and take control of their nervous system, creating a mindless 'zombie' that submits to the will of the headcrab. Fast zombies have a number of key differences to standard zombies, including increased speed and agility.

Since fast headcrabs lack a beak, it is unknown how they take control of their hosts. They could possibly use their longer than average legs to burrow deep into the host's body and manipulate the nervous system through the spine rather than directly manipulating the motor cortex of the victim.