Yemrek, the Tilling Maw

Vigilance, Devoid

{w}{g}{g}, Exile a card from a graveyard: Put a spawn counter on target land. That land becomes a 0/1 Eldrazi Spawn creature with "Sacrifice this creature: Add {1} to your mana pool." It is still a land.

Whenever an Eldrazi Spawn you control is sacrificed, you may return a card from exile to its owner’s graveyard.