Will o’ wisps — also called marsh lights, hob lights, or marsh candles — are a type of fey found in the northern forests of the world. They have a soft, spongy body that projects a protective electric field. The energy emits a powerful light, causing will o’ wisps to appear as glowing orbs of green, yellow or blue.
Among the most vicious of fey, they delight in leading travelers into the deep wilderness. When utterly alone, victims are zapped with bolts of lightning-like energy. Once dead, the prey’s bodily energy is consumed and the corpse becomes wilted and shrunken.