ghostly

ˈɡəʊs(t)li

adjective

of or like a ghost in appearance or sound; eerie and unnatural.

a frightening, ghostly figure with a hood

ghostlike,spectral,phantom,wraithlike,phantasmal,phantasmic,unearthly,unnatural,supernatural,other-worldly,insubstantial,illusory,unreal,shadowy,eerie,weird,uncanny,mysterious,magical,mystic,strange,abnormal,freakish,frightening,spine-chilling,hair-raising,blood-curdling,scaring,terrifying,petrifying,chilling,sinister,eldritch,creepy,scary,spooky,freaky,rum