A villain/overlord so evil that he does, in fact, eat babies.
This is often used as an indication that a character is well beyond the Moral Event Horizon. Can be Played for Laughs, given the sheer over-the-topness that the accusation of "baby eating" usually invokes, but can also be Played for Drama (or for sheer Squick).
This is a subtrope of I Am A Humanitarian as well as of Would Hurt a Child. [...] [tvtropes.org]