- "Every time you heard someone say they saw a ghost or angel, every story you've ever heard about werewolves, vampires or aliens is the system assimilating some program that's doing something they're not supposed to be doing."
- ―The Oracle
The Oracle, in her second meeting with Neo tells him that everything within the Matrix has a function and a place, and are generally invisible and innoccuous. "But", she continues, "the other ones, well, you hear about them all the time". The Oracle is not talking to the viewing audience, but to Neo and his own life experiences as a bluepill within the Matrix.
After the Merovingian spurns Neo, Trinity and Morpheus away in their attempt to find the Keymaker, Persephone aids them by taking them to the Keymaker's cell. On the way the group meets with two men who are watching a movie about vampires. Persephone explains that the two men come from a much older version of the Matrix that the Merovingian has kept around for his own devices She tells the trio that the men are extremely hard to terminate, and proceeds to terminate one of them using a gun armed with silver bullets. Silver is supposedly used to kill a werewolf.
Later, Neo must defend himself and the Keymaker by eliminating several men, all of whom have physical characteristics suggestive of being vampires. Meanwhile, Trinity and Morpheus escape with the Keymaker, but are being pursued by two men who can dematerialize at will, like a ghost, to resist physical attack.
Based on the comments and behaviors of the Architect, Persephone, and the Merovingian, it is strongly suggested that the Architect used virtual monsters to frighten the inhabitants of the earlier versions of the Matrix. Given that the Merovingian has kept these monster programs with him and in check, it is probable that the Merovingian may have had some part in the creation of the second failed attempt at a stabilized Matrix, or at least was around at the time of its activation. The Merovingian's age ("One of the oldest of us") is confirmed by the Oracle as part of her instructions to Neo on how to retrieve the Keymaker.