The very first enemy to have no means of attacking directly, the necromancer is a support type enemy. Alone, the necromancers try to run away from you and are easily defeated, but with other enemies they can prove to be a worthy foe.
They will periodically raise dead Freaks up from corpses. They can also turn destroyed objects and other enemy's corpses, including other Necromancers into living Freaks. The ability has a small area of effect and has no apparent range. The only limit is the Necromancer's line of sight, not obstructed by walls. Necromancers shoot an invisible projectile that has extremely high speed and after reaching a corpse, turns it into a Freak. This can often take the player by surprise, flanking them from a "safe" area that has previously been cleared out.
If you see enemies coming back to life, you should find any Necromancers and kill them as soon as possible. If they are not dealt with quickly, they will wear down your health and ammunition with a never-ending stream of enemies from all directions.
Melting's active ability can nullify the effectiveness of Necromancers, as they are useless without corpses to revive.
Occasionally, it is possible to find a "Necromancerless labs" containing zero Necromancers.
- The Necromancers were scientists that experimented on mutants, which eventually led to turning themselves into something that resembles a mixture of Eyes, Robot, and a Bandit.
- In update #74 the Necromancer's ability was changed to affect an area instead of just one corpse. It also got a new area of effect animation. This was done to prevent them from instantly reviving enemies right under your character.