Y'Mala, Keeper of Bloodlines.

When Y'Mala, Keeper of Bloodlines enters the battlefield, choose a creature type. Creature's in your graveyard are the chosen type in addition to their other types.
Whenever a creature you control blocks, put the top four cards of your library into your graveyard.
{4}{b}{g}: Choose a creature type, return all creatures of the chosen type from your graveyard to play.