Take it back to its roots -- Pre as latin for before and Decessor, rooted in decessus for decease. So, predecessor becomes "One who dies before" (or, more literally, one who retires from the village before).
So, opposites. Post as a latin prefix for after, and Animatus, a root for giving life to.
So, how about "Postanimator?" Or, if we want to be sticklers for standard English word construction, "Postanimated."