Grimoire of the Dead

{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.

Starter Commander Decks

The List

Commander 2019

Innistrad

“Creature cards” includes each card with the type creature, even if it has additional types, such as artifact.