Grimoire of the Dead [Commander 2019]

Set: Commander 2019 Type: Legendary Artifact Rarity: Mythic Cost: {4} {1}, {T}, Discard a card: Put a study counter on Grimoire of the Dead.{T}, 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.