fray
make someone's hair stand on end
geek out
scarecrow
put the shits up someone
do someone a frighten
scare the hell out of
scare the living daylights out of
scare the life out of
put the heart across one
freak out
run scared
fear
make someone's jaw drop
frighten the horses
curl someone's hair
put the wind up
spook
make someone's flesh creep
funk
spook out
flay
make someone's skin crawl
get the wind up
alarm
have the wind up
scare the shit out of
unnerve
alert
skeeve
scare the pants off
disquiet
jolt
creep out
glope
turn a hair
startle
frighten
put the cat among the pigeons
give pause
chutter
get a rise out of
frighten the piss out of
preoccupy
scare someone to death
frighten the life out of someone
rattle
hagride
not bear thinking about
worry someone sick