What did Mr White mean in the end of the story The Monkeys Paw when he told his wife not to let it in?

I remember that from when I was a little kid. When she asked to have her soon come back, he came back alright, but not exactly a human form. Remember the bloodly claw marks on the door? that was the son. If she'd let im in, I don't think that he would of exactly hugged her. He was probably something like a zombie.