When Grass-Knoll enters the battlefield, sacrifice it unless you pay 3 life.
, : Add , or to your mana pool.
, Sacrifice Grass-Knoll: Target creature gets +2/+2 until end of turn.
, 
: Add 
, 
or to your mana pool., Sacrifice Grass-Knoll: Target creature gets +2/+2 until end of turn.
