(: Add or to your mana pool.)
Underground Prairie enters the battlefield tapped.
, Sacrifice a Swamp: Add to your mana pool.
, , Sacrifice Underground Prairie: Prevent all combat damage that would be dealt this turn.
: Add 
or 
to your mana pool.), Sacrifice a Swamp: Add to your mana pool., , Sacrifice Underground Prairie: Prevent all combat damage that would be dealt this turn.
