Creepiest Movie Children - Rotten Tomatoes
Interview with the Vampire (1994)

Created by Tom Cruise's vampire Lestat as a "daughter" and playmate for Brad Pitt's Louis, blonde, ringlet-haired Claudia -- played with preternatural relish by Kirsten Dunst -- turns out to be arguably the most evil bloodsucker of them all. It's Claudia who baits her master into drinking the blood of two already-dead victims, then slitting his throat as an act of revenge for being created.