Other Zombie creatures you control get +1/+1.
, : Exile target creature card from a graveyard. Create a 2/2 black Zombie creature token.
10/1/2009 Cemetery Reaper grants +1/+1 to all other Zombie creatures you control, not just the ones its ability puts onto the battlefield.
10/1/2009 The creature card in a graveyard is exiled as part of the activated ability’s effect, not as a cost. If that card has left the graveyard by the time the ability would resolve, the ability doesn’t resolve and you don’t get a Zombie token.