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