Wouldn't say boo to a goose.
A shy or nervous person.
Skeleton in the closet/cupboard.
To have an embarrassing secret about your past.
Like a bat out of hell.
To move extremely quick without thought or in a panic.
Night owl.
A person who tends to stay up late.
Over my dead body.
To refuse to do something.
To dig one's grave
To be responsible for one's downfall or ruin. It's a way of expressing that you've made a big mistake.
To make someone's blood boil.
To make someone very angry.
Witch hunt.
To unfairly seek to damage others, perhaps because of a false view of their beliefs.
Skeleton crew
The smallest number of people needed for a business to operate.
Drop dead gorgeous.
Someone very good looking.
Graveyard shift.
A work shift that happens overnight.
To scare the pants off someone
To frighten someone a lot.
Scaredy cat.
Someone who is easily frightened.
Playing devil's advocate.
To present the other side of an argument even though you don't personally support it.
In cold blood.
To do something deliberately in a ruthless manner.
A snowball's chance in hell
There's no chance at all.
To smell a rat.
To suspect that something wrong or dishonest is happening.
To spill your guts.
To confess everything.
Ghost town.
A deserted place where there are few or no people.
To be scared stiff.
To get so scared you're not able to move.
Stabbed in the back.
To be betrayed by a friend or colleague.