Here is a list of scary words that will improve your vocabulary and will help you write a scary story or spooky poem.
(1) Eerie
Suggestive of supernatural .
(2) Specter
Ghostly figure
(3) Haunt
Follow stealthily or recur constantly
(4) Uncanny
Surpassing the ordinary or normal.
(5) Weird
Unusual or strikingly odd
(6) Terror
an overwhelming feeling of fear and anxiety
(7) Monster
an imaginary creature usually having human and animal parts
(8) Pall
burial garment in which a corpse is wrapped
(9) Horrendous
causing fear or dread or terror
(10) wraith
a mental representation of some haunting experience