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

Half Life, the Gathering Day 8: Zombies

Zombie, Half-Life Wiki

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

Wiki: monster_zombie - TWHL: Half-Life and Source Mapping Tutorials and Resources

Half-Life 2 - Wikipedia

Zombie, Half-Life Wiki

Headcrab Lifecycle that makes sense : r/HalfLife

Fast Zombie, Half-Life Wiki

Combine Hazmat Worker - Combine OverWiki, the original Half-Life wiki and Portal wiki