It was originally supposed to be about crib death yeah.

And all those folklorish creatures that cause that, or just anything coming around at night like the sandman have some creepy motivations like that. Like goethe's erlkonig, too. Similar thing, about a kid dying to a creepy supernatural being. Or is it just his feverish imagination?

I don't think the song is about that as such, but I do see why you'd draw that link.