William

William was a note writer and friend of Matt Singer, before being betrayed by him and being locked in a room filled with zombies. He later reincarnated into a large, muscular zombie named The Husk, which serves as the secondary antagonist of the game, and the final boss of Chapter 7.

Overview
William believed that Matt was his friend, and trusted him, but Matt eventually locked him into a room, revealing that he only used him for his supplies, and flooded the room with zombies, killing William and infecting him.

Gameplay
Throughout the game, The Husk will randomly chase the player throughout locations, but in some locations where he doesn't appear, William's notes are found, the player learns more and more about him throughout these notes. His final appearance is near the end of the game, as an effort for Matt to avoid his confrontation, he deploys the Husk to fight the player. The Husk, for the most part, mainly behaves as a large zombie, but with some unique attacks. The last time he is seen is as the final boss in Chapter 7, where he has some extra attacks and abilities, but is still able to be taken out by the player.

Trivia

 * As a human, he has met Robert, who gave him ammo which was later stolen by Matt.