humans. Along with being able to move faster than normal zombies, zombines also have the unique ability to pull out a live grenade and charge the player, killing themselves in the process. It is as yet unclear as to what specific function in the Headcrab ecology or reproductive cycle the zombification process serves. Armoured Headcrab Half-Life: Alyx introduces a headcrab variation whose back is covered by a bulletproof shell with dark bulbs and thick spikes. To fight one effectively, the player must target the creature's weak underbelly when the opportunity presents itself, such as when the crab balances on its hind legs in preparation for a jump, or when it lands on its back after jumping, after which it takes a moment for the headcrab to recover its posture. A single pistol hit to the exposed underbelly can kill the creature instantaneously. Appearances Half-Life Headcrabs are one of the first enemies introduced in Half-Life. They are frequently encountered by players throughout Half-Life and its three expansions, Opposing Force, Blue Shift, and Decay. They also see appearances in the official port of Half-Life, titled Half-Life: Source, as well as the third-party fan modification remake titled Black Mesa. Because the games are remakes or ports, headcrabs play essentially the same role as they do in the original Half-Life. Half-Life 2 In Half-Life 2, the Earth-occupying Combine use headcrabs as a biological weapon against the human Resistance. A coffin-like missile is filled with headcrabs and fired from a mortar (as seen in Half-Life 2: Lost Coast). The Combine bombard distant areas with these missiles, and the payload of each shell is released to infest or kill nearby victims. Half-Life 2 also featured the first appearance of Dr. Kleiner's "pet" headcrab. Referred to as "Lamarr" (after actress and scientist Hedy Lamarr), it serves as an important plot device for several scenes in the game, most notably in the second chapter of the game, when, by damaging the teleporter that the player is in, causes it to teleport Freeman outside Kleiner's lab, forcing escape through City 17's canals, and also alerting the Combine to the player's presence. The headcrabs found in Half-Life 2 differ slightly from those found in Half-Life. For example, they are smaller and they no longer have exposed teeth or intestines. In Half-Life 2 headcrabs drown within seconds in deep water and easily survive in contaminated pools, while in Half-Life they can