Answer: spookiest

AnswerCrossword Clue
SPOOKIESTMost hair-raising
SPOOKIESTMost eerie
spookiestSPOOKY, scary (frightening, also SCAREY)
spookiest(of a person or animal) Easily frightened; nervous
spookiestSinister or ghostly in a way that causes fear and unease