kel·pie [ kélpee ] in Celtic folklore, a malicious water spirit that takes the form of a horse or handsome young man and lures humans, generally young women, to death by drowning and then devouring them. doppelgänger [ˈdɒpəlˌɡæŋər] in folklore, is a spirit usually shaped as a twin, shadow or a mirror image. A doppelgänger may embody itself years after it's original body's death in it's replica. (Sequel, Water In My Lungs: Sins of the Father)