When Scrub Knoll enters the battlefield, sacrifice it unless you pay .
: Add to your mana pool. Return Scrub Knoll to its owner's hand.
: Scrub Knoll becomes a 2/2 black Horror creature until end of turn. It's still a land.
.
: Add 
to your mana pool. Return Scrub Knoll to its owner's hand.
: Scrub Knoll becomes a 2/2 black Horror creature until end of turn. It's still a land.
