(: Add or to your mana pool.)
Centaur Swamp enters the battlefield tapped unless you control one or more creatures.
, : You gain 2 life.
, , Sacrifice Centaur Swamp: Put a -1/-1 counter on target creature.
: Add 
or 
to your mana pool.)
, : You gain 2 life., , Sacrifice Centaur Swamp: Put a -1/-1 counter on target creature.
