Spirits of concentrated hatred that fly around open fields and graveyards. Often they are blue- or white colored, and they wear a robe and a lamp.
These are the Ghosts of the Zelda series.
The POes in this game are mostly floating around, and when they hit Link, hit will only cause damage, nothing more. And when Link defeats a Poe, nothing happens. They are just normal ghost-like enemies floating in graveyards.
===Ocarina of Time===¨ The Poes of Ocarina of Time are making some float-noise when they move around, and they attack by swinging the lamp they have. When Link defeats a Poe, the Poe Spirit will stay in the "place of defeat" for a while, and Link is able to pick it up into a bottle. The Poe souls are sold in a shop, too.
The Poes of Twilight Princess are invisible to a normal human, but the wolf is able to see it by using the wolf sense. The Poes wear a scythe, and they wear a tall robe, and it's able to hit them only by jumping, because we all know, that the Poe's are able to float in the air. When Link defeat's a Poe, he will get a Poe's Soul. Those are used to free Jovani.