Starfinder: Wireless Ghost
Wireless Ghost are undead creatures which for some reason have a strong tie to computers and other similar wireless devices. These creatures require a wireless system in order to exist. The only way to permanently destroy these creatures is to destroy the computer or wireless device they are connected to.
Physically, these creatures appears to be a projected video image of a naked and bald humanoid. These video images flicker and go out of focus often and the creature looks as if it is suffering from early stages of decay.
While in this state only magical weapons and spells will have any effect on the creature.
It is when the creature takes corporeal form that other attacks can affect it, but at the same time it can attack and interact with the world around it. While the creature is corporeal, they will use their fists to bash through barriers or attempt to knock away weapons or even grapple with a target.
If it takes enough damage to reduce it to zero hit points, the creature appears to go entirely fuzzy, like a TV screen or monitor filled with static and it disappears with a shriek that can shatter glass. What actually happens is that the creature disappears back to its home device. The creature then disappears for 24 hours while it re-forms in its wireless home. Once it has re-formed it can attack once again.
Once it has taken corporeal form, the monster can attack. It has two special attacks. First it can use its Vampiric Field. The other attack is it stand up in front of its target and initiate a ‘soul’ drain. Anyone who can view the ultraviolet spectrum will see what appears to be a video image of the target being pulled from their body and being absorbed into the body of the incorporeal monster.
To date, there is no way to communicate or bargain with these creatures. They don’t appear to be intelligent, although they do know how to hide or keep their wireless devices safe, and they have no interest in anything but the hunt and kill.