The Crimson Head (クリムゾンヘッド,kurimuzon-heddo?) is one possible mutation a zombie can experience, depending on the strain of t-Virus it is infected with. The V-ACT process is responsible for its crimson skin, earning it its name.
Crimson Heads were the result of the unforeseen effects of the Epsilon strain on the human body. The strain, developed for the Tyrant Project, was released in the Arklay Laboratory during a lab accident. As the facility's staff had no experience with Crimson Heads aside from the brief, violent encounter with Crimson Head Prototype 1, they were at a disadvantage, and an informal policy became to destroy the bodies of Zombies to prevent further mutation.