Thanquol, Gnawing Death

When Thanquol, Gnawing Death enters the battlefield, you may search your graveyard
for two Skaven cards. Place one in your hand
and the other onto the battlefield tapped.
{t},{b}{b}, sacrifice a creature: Return this card
to your hand.
"Is lightning usually green?"
—Noth Grimscale, late Druchii commander