Nobody for sure knows what this song is about but that is how Kurt would have wanted it.
But here are some guesses/facts/reviews about \"Negative Creep\" from songfacts.com :
This is about an individual who always looks down on things. Kurt Cobain said: \"I just always saw myself as a negative person.\"
just to clear it up he didn't have a daughter at the time they released the song. The \"daddy's little girl...\" part is definitely just one of those filler lines he had lying around and decided to throw it in there, he does that very often(a lot of songwriters do actually). i don't see how there can be a real significance to this line.
Velvet Revolver covered this on the B-side to their first single, \"Slither.\" They also frequently play the song live.