Grimm Pools

Grimm Pools enters the battlefield tapped.
When Grimm Pools enters the battlefield, return
a land you control to its owner's hand.
When Grimm Pools enters the battlefield, sacrifice
it unless you pay {1}.
{t}: {b}{b}
{x}{x}{t}: Create X black Grimm creature tokens
with your choice of flying, trample, or deathtouch