Zombieman

"Just a few days ago, you were probably swapping war stories with one of these guys. Now it's time to swap some lead upside their head."

- Doom instruction manual

The Zombieman (also known as former human, trooper, former trooper or, sometimes, former soldier in the game manuals) is a possessed and/or undead former soldier which has been turned into a zombie during the invasion from Hell, encountered in the classic generation of Doom, Doom II, and Final Doom.

Doom RPG
In Doom RPG, the Zombieman appears as the "zombie" monster class. There are three different forms, identified by color: They are weak against axe attacks.
 * Zombie private (brown)
 * Zombie lieutenant (blue)
 * Zombie captain (normal colors)

Trivia

 * In Doom II for the Game Boy Advance, a red blood splatter, half-way covered in green, appears in the Zombieman's death animation.
 * Their Rifles, were at one point accessible to the player (as their original starting weapon)
 * In the novels, the Rifle is known as the M-211 SIGCOW, and uses 10mm rounds.
 * In PlayStation Doom, their gunshot damage is increased somewhat, up to a maximum damage of roughly 21. The manual also lists the name of this enemy type as "Former Soldier", as opposed to "Former Human" as in the PC versions' manuals (or "Zombieman" as in the enemy cast at the end of the game).