Monsters, mobs, enemies, and even zombies (with lowercase 'z') refer to the various dangers players may face in event game modes. They are themed for each season they are a part of: Halloween, Christmas, and Easter. The term "zombies" originated from the original ZBR event, Zombie Royale, in which the enemies present were zombies. These enemies were deprecated in favor of other enemy types with following events, even renaming Halloween's event to Monster Royale; however the zombie name has stuck with players, even still living on in the names of ZBR and ZDC events. A zombie enemy does still exist in Easter as the main enemy type sporting a pink bunny suit. In general conversation, the use of "Zombie" versus "zombie" is a difference of if the player is speaking of the Zombie enemy itself, or referring to enemies as a whole.
Since June 2024 the term "aliens" has also been used. For sake of neutrality, the term "enemy" will be used here onward.
Enemies all spawn with nothing in hands (Fists equipped). Upon spotting a player to aggro onto, enemies will equip the weapon they are assigned if they have one. This weapon will never be put away once it has been pulled out. Separate to weapons an enemy may possess, some enemies have special aspects that differentiate them from one another. These introduce both variety and more danger to the battlefield. These aspects include:
— Basic enemies with no aspect
— Enemies with 35% damage reduction
— Enemies with 3× jump height
— Enemies that self-destruct dealing explosion damage
— Enemies that self-destruct leaving acidic gas clouds to deal continuous acid damage
— Enemies that break down into smaller duplicates, dying only when too small
— Autonomous vehicle units that deal gas damage
— Giant boss enemies with massive HP
While enemies may need a High Jump aspect to normally jump at an increased rate, every enemy in ZDC is capable of jumping more than 10× the standard height if an aggro'd player is too high up, typically being on a high building.
Each event will have five different enemy types. Between years, these may switch (for example Halloween has seven different types of enemies, but only five will show in a single event). Of the five variants present, the total number spawned may scale with the number of players alive in a lobby. Additionally, the max HP of a Boss scales with the number of alive players when one spawns.