Zombie, Half-Life Wiki

A Zombie is a common enemy featured in the Half-Life series. It is the result of a Headcrab attaching to the head of a human and taking control over its victim's body, this incapacitates the host, and renders them a "Headcrab Zombie," or a "Necrotic", as they are referred to by the Combine Overwatch. Ordinary Zombies are often referred to as Standard Zombies to distinguish them from the other types of Zombies, such as the Gonome, the Fast Zombie, the Poison Zombie, the Zombine, and the Armored Z

Alien Grunt - Combine OverWiki, the original Half-Life wiki and Portal wiki

Houndeye - Combine OverWiki, the original Half-Life wiki and Portal wiki

npc_fastzombie - Valve Developer Community

Headcrab zombies, VenturianTale Wiki

Headcrab, Monster Wiki

Ravenholm - Wikipedia

Armored Headcrab, Half-Life Wiki, Fandom in 2023

Npc zombie - Valve Developer Community

Headcrab (zombie edition), HLEU (Half-life Extended Universe) Wiki

Headcrab Lifecycle : r/HalfLife