Happens at night

I feel something under my bed
I hear his sound and feel his breath
something moves, creeps beneath me
something big, but I cannot see

I hear a roar, but nothing shows
I'm still tense and my fear grows
strange shadows across the light
why these things happen at night?

I see a shadow running to the wall
I begin to scream as he walks
he stops, turns and looks at me
he goes out, leaving me scared

Sleep, my son, was a nightmare
Go back to sleep and don't be scared
I'll sleep and turn out the light
son, these things happen at night