The Zombine, a portmanteau (coined by Alyx Vance) of Combine and Zombie, is the result of a Standard Headcrab attaching to the head of an Overwatch Soldier. The appearance of the Zombine is taken as evidence that the Combine were losing control of City 17 following the near-destruction of the Citadel. Prior to the human uprising, there were very few headcrabs in the city, only found in areas that had fallen into disrepair. However, thanks to the prolific use of headcrab shells against rebel safehouses before and during the uprising, headcrabs came to infest large areas of the city, particularly its underground sections. Zombines are first encountered in Half-Life 2: Episode One, when Gordon Freeman and Alyx Vance stumble upon a troop train in the severely headcrab infested City 17 undergro