Ghost People

The  are the main enemies in the Fallout: New Vegas DLC Dead Money. They inhabit the area surrounding the Sierra Madre. There are three variations of Ghost People: Ghost Harvester, Ghost Trapper and Ghost Seeker.

Background
Protected by Hazmat suits, yet morphed into something no longer quite human, the Ghost People are the only ones to walk the Cloud. Anyone who isn't savagely killed when they first hear the insidious screaming of the Ghost People is dragged away to a fate that as yet remains uncertain, but is probably much worse than dying in the streets.

They are very mysterious: they don't talk to their victims, they're evidently quite agile, they're highly territorial, and they have glowing green eyes. They don't die very easily - to really kill them you have to decapitate, dismember, blow them up, burn them (although this is difficult due to their 85% immunity to fire) or feed them to Dog. A terminal states that hazmat suits were used when a red cloud of what was supposedly rust hospitalized a worker. The suits forced the workers to communicate using sign language. After venturing into the cloud the seals on the suits corroded forcing the workers to cut open their suits to get out.

It is likely (though not confirmed) that the Ghost People are comprised of residents and workers of the Sierra Madre before the war that failed to escape their suits. The suits are likely to be the reason that none of them talk to their victims. If so, it is possible that the Ghost People are a variation of ghouls, trapped inside their suits, near immortal, due to large amounts of radiation. It is implied the suits are difficult to remove after exposure to the Cloud, and impossible to remove them alone. This further supports the idea that the Ghost People are the workers and residents of the Sierra Madre casino

You may not see them on your compass, but they see you, as their Perception is 10.

Interactions with the player character
All Ghost People are hostile to the PC. To kill them you must remember the Four D's: decapitate, dismember, disintegrate, or Dog. If Dog is your companion he will eat them when they are knocked unconscious. They usually carry a Knife spear, Bear trap fist, Gas bombs and/or Throwing knife spears.

Ghost People are usually to be found in ones or twos or occasionally in small groups. They are highly agile and will constantly be moving around during an engagement; this, coupled with the damage resistance of their HAZMAT suits, makes them difficult foes to take down. Your best tactic is not to go toe to toe with them, especially if surrounded, but to fight them at range(and preferably above them) with bullets, spears, and whatever explosive devices you have on hand. For close quarters combat later in the game shotguns and laser pistols are good options for these adversaries, as the former will usually cause a limb to be crippled upon death while the latter has the chance to disintegrate them into a neat pile of ash. Also, if you have the ammo and the strength, the automatic rifle that you find is also a good choice, as it will cut down a Ghost Person very rapidly. Because of the inaccuracy of this weapon, it is best to take on foes in close quarters (and best one Ghost Trapper at a time). You will still need to move close in to dismember them after utilizing that particular weapon, however (unless you have already disintegrated their head). Difficult as they are, once armed with a bear trap fist, a player can make short work of a group of them even with a below average unarmed skill.

The Ghost People are violent, as said in the collectors edition book (DLC section) and they wear hazmat suits of Russian origin and have turned into a nasty, unspeakable horrors inside of their suits, most likely due to large amounts of radiation, and the Cloud. It is unknown how they came to possess the suits, but they are not chemical suits, as Father Elijah points out that the gas just destroys those. There is a terminal later on in the DLC that has notes from workers that were maintaining the Sierra Madre stating that new uniforms were delivered and they worked like a charm, however later on it tells of them starting to get rough and stiff. This could be a possible origin of the Ghost Peoples' HAZMAT Suits. Note: It's possible that the Ghost People are Ghouls, as when they're dismembered, they spew green blood like ghouls, and the small bits of the limbs that were cut off are wrinkled, like a ghouls's.

Appearances
Ghost People appear in the Fallout: New Vegas add on Dead Money.