The poor boy was scared stiff when he saw a spaceship flying through the sky.

Slang of the day:  scared stiff

Meaning:  so frightened that you are unable to move

Usage:  I was scared stiff when I saw who was at my door.

Dialog: 

Mandy – Did you hear the wind howling last night from the hurricane?

Angie – I sure did, I was scared stiff.  How about you?

Mandy – Not me, I went to the beach to watch the waves.

Angie – You are nuts.

Mandy – Yup.