Grimoire of the Dead

Aufzeichnungen der Toten (Grimoire of the Dead) (de)

Legendary Artifact (CMC 4)
, , Discard a card: Put a study counter on Grimoire of the Dead.
, Remove three study counters from Grimoire of the Dead and sacrifice it: Put all creature cards from all graveyards onto the battlefield under your control. They're black Zombies in addition to their other colors and types.