All the zombies in the game possess varying degrees of intelligence. As opposed to the average Hollywood zombie, which is mute, the zombies in the game retain their vocal chords, as such, they can talk. They are portrayed as conceited and trash-talking creatures, often using vulgar phrases such as "Let me fuck your father!" and other phrases which are humorous, such as "It's nearly nine o'clock, you should go home!" The zombies are unique as opposed to other zombies in Hollywood in that they can recognize former allies and will still aim to kill them, such as when Mr. Fitzgibbon recognizes Juliet as one of his former students. Some zombies appear to be more dim-witted than others, i.e. the ones at the O'Bannon Farm, who are portrayed as immensely obese and sluggish. Likewise, the zombies in San Romero city are faster, slimmer and more agile and cunning.
Most zombies in film will simply blunder through barriers or, upon realizing their route is blocked, will stumble mindlessly around beside the barrier until a human victim comes their way. The zombies Swan created were cunning and intelligent such as when a troop see Juliet over the rooftop, they run downstairs and onto the alley to catch her, and there are zombies exercising on the gym treadmills, waiting for Juliet to appear so they can try to kill her.
Necromancers are humans who have control over conjuring, communicating with, and summoning the undead. Whether or not this is an inherited ability a human is born with or something that they learn over time is unclear. So far, the only known necromancer is Swan, who became vengeful and used his abilities to break the barrier between the Human World and the Rotten World.
As is seen in-game, Swan summons five zombies to the world from the Rotten World. As informed by Sensei Morikawa it is said that the Rotten World is full of zombies, these in which Swan has summoned by ritual.
Unlike most zombies in games or in the media, the Dark Purveyors posses powers that go beyond the expected zombie. The Dark Purveyors are the most powerful and intelligent zombies seen in the game. As said by Swan, the zombies are capable "rotting" anything in their path, transforming them into the undead. Each Dark Purveyor possesses a unique power of that is determined by their music genre.
Each boss is also capable of counter-attacking each of Juliet's Chainsaw attacks, making them more difficult to kill. They are used as a sacrifice in order to summon a final zombie of the name "Killabilly" which is to reach Swan's goal to annihilate all of humanity.