What a voice.
A voice which, had I heard it as a child, would have turned my nights into seasons of horror: tender and tremulous but loaded to bursting with unspoken menace. It has something to do with the stresses being all out of whack and its velventeen softness being pricked by the occasional note of hysteria like a sadistic pianist slamming down on D minor in the middle of a lullaby.
The Simpsons smacked the nail right on the head when they had Walko reading from Good Night Moon to a gaggle of terrified kindergarten kids. Also check out his cameo as Captain Koons in Pulp Fiction. Cracking stuff.