12 words to describe something scary/shockingly frightening

spooky

creepy

eerie

bloodcurdling

spine-chilling

spine-tingling

stomach-churning

hair-raising

bone-chilling

gut-twisting

gory (specifically used for something that is bloody)

horrific

ghastly (used mostly for appearances)

ghoulish (a ghoul, in stories, is an evil spirit that open graves and eats the dead bodies in them. This word can be used disapprovingly for a person who takes a morbid interest in death and disaster.)

gruesome