(: Add or to your mana pool.)
Merfolk Caves enters the battlefield tapped unless you sacrifice a creature.
, , Sacrifice Merfolk Caves: Return target creature you control to its owner's hand.
, Sacrifice a Swamp: Add to your mana pool.
: Add 
or 
to your mana pool.), , Sacrifice Merfolk Caves: Return target creature you control to its owner's hand., Sacrifice a Swamp: Add to your mana pool.
