Berenice is the name given to the maid in Season 8: Dreamland, and of the episode in which she appears (s8e2). She does not really constitute a dream persona as she is dead. She was tragically killed as a consequence of a botched abortion, after Cecil got her pregnant. Charlotte Vandertunt wants to use her remains in a ruse to fake her own death, as she happens to have perfect teeth. Her name may be a reference to the 1989 movie 'Weekend at Bernie's' in which 2 employees try to convince people their dead boss is alive by dragging him around everywhere.