Poltergeists are a low-level undead monster found in the 1986 video game Might and Magic Book One: The Secret of the Inner Sanctum. They only have a low armor class and average hit points, but make up for this with speed and the ability to attack twice per turn. Even so, their attacks do little damage to your party, making them not much of a threat. Another ability they possess allows them to advance to the front lines should they be positioned in the back, though this makes them an easy target for your melee classes. They are also susceptible to the Turn Undead spell.
Oddly, when the game was ported to the Nintendo Entertainment System, the new sprite given to them became a disembodied eye surrounded by what appears to be a barrier of electricity.