The Zombie appears as a replacement for the Possessed zombies in Doom (2016). A stronger variant, the Mecha Zombie, appears later in the game and has an arm cannon for ranged attacks.
Possessed by the influence of Hell, once human underlings that follow in Hell's ranks are those that have been corrupted and deceived by its power, forsaking their own humanity. Those who have fully succumbed to Hell's will cannot be saved, becoming mindless, grotesque contortions of their former selves.
The normal zombie has two appearances, the first being a possessed human. Notable features of the zombie are the pentagram on its forehead, its elongated fingers, and decrepit appearance. A version of this zombie wearing cultist robes can be found throughout the Cultist Base. These variants are most commonly found on Earth. The second variant of the zombie is the Unwilling from Doom (2016), and serve the same role as the human zombie, instead appearing in more exotic locations, such as Exultia and Taras Nabad.
The Mecha zombie is notably taller than its normal counterparts and has obvious signs of machine enhancement around its body. The most obvious difference being the arms cannon that has been grafted to the zombie. It also possesses a metal claw hand on its left arm and has other mechanical additions in various places.
Basic zombies will do little more than slowly stumble toward the Slayer and attempt to bite/slash him when within range, but are otherwise helpless. They can be killed extremely easily, and serve very little threat.
Mecha Zombies pose a greater challenge. Their arm cannon serves as a rapid-fire energy weapon at long distances, and a flame-thrower at close range. When next to the Slayer, the Mecha Zombie will take a swipe at them with their left hand.
Outside of its increased arsenal, the Mecha Zombie possesses the same flaws as its lesser brethren. It is ridiculously slow, and while capable of taking a higher amount of damage, they can still be killed with ease.
Neither are real threats, and are more of a useful tool than a true enemy. Entire groups of Basic Zombies can be gibbed with a single sticky-bomb, making them useful targets for the flame belch. While the Mecha Zombie cannot be instantly defeated with sticky-bombs or scope-shots, they will instantly stagger them instead, making them good targets for a quick glory kill.