Centaur Reef enters the battlefield tapped.
, Pay 1 life: Add or to your mana pool.
, , Sacrifice Centaur Reef: Draw a card.
: Centaur Reef becomes a 2/2 blue Cephalid creature until end of turn. It's still a land.
, Pay 1 life: Add 
or 
to your mana pool.
, , Sacrifice Centaur Reef: Draw a card.: Centaur Reef becomes a 2/2 blue Cephalid creature until end of turn. It's still a land.
