They are also relatively slow-moving and their attacks inflict very little damage. Physically, headcrabs are frail: a few bullets or a single strike from the player's melee weapon being sufficient to dispatch them. Under the headcrab's body is a large rounded mouth surrounded by mangled, rigid flesh with a sharp claw-like beak. Their pair of large frontal claws are for attacking, and as additional support when standing still. 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. They also appear to be smarter than normal zombies, since they understand the use of grenades, using them in suicidal charges against any unlucky victim.Headcrabs are depicted as parasitic lifeforms roughly 2 feet (0.61В m) long. It wears the same clothes as a normal soldier, a blue uniform with body armor, and is stronger than the average zombies due to the implants given to the soldier before being infected. The result of a headcrab controlling a Combine Overwatch Soldier, the Zombine is encountered in Half-Life 2: Episode One and Half-Life 2: Episode Two. They can also be ridden by a maximum of four 'poison headcrabs', and can throw three of them at the opponent. This zombie like a standard version can continue attacking after being cut in half.Д«loated by huge amounts of poison, tougher and slow, this zombie is possibly the most dangerous of all, since the parasite that creates it is extremely venomous, enough that one hit after initial exposure is guaranteed to be lethal. The headcrabs that create them, called 'fast headcrabs', often survive even after the zombie itself is killed, continuing to attack. Lacking any internal organs or skin, those zombies can easily jump over enormous distances, climb walls or attack with extraordinary speed, while being just as resilient as the normal zombies, taking at least two shotgun shells before dying. They only appear in the expansion 'Half-Life: Opposing Force'. They are tougher than normal zombies, but rarer. Their claws are elongated, and the mouth in the chest has fully developed, with real, sharp teeth created from the host's ribs. Additionally they can throw the objects and when taken enough damage the standard headcrab with detach from the head and attack on its own.ДЄfter some time passes, the host is mutated even more heavily by the parasite, becoming a 'gonome'. The zombie can be also cut in half with a sawblade and will continue to crawl towards the prey. Otherwise, with liberal application of explosives, or careful use of a crowbar, they are not a big problem. While a single zombie isn't a real threat, a mob of them is extremely dangerous, if one finds themselves surrounded. The chest is opened, forming a 'mouth' with ribs used as teeth, and the hands are transformed into claws, used to rip apart the prey. The standard zombie is created by a standard headcrab latches onto a suitable host. Depending on the host, type of headcrab, and time since infection, five different kinds of zombies may be created.

While the headcrab controls movement, the host, still conscious, can feel what their body is doing, scream in pain especially when set on fire, or beg to be killed. Zombies are created when a Headcrab attaches to the head of a suitable host and takes control over its victim's body, rendering the host a 'Headcrab zombie,' or 'necrotic', as they are referred to by the Combine Overwatch.

Half life poison headcrab