Bog Ravine enters the battlefield tapped unless you pay .
: Add or to your mana pool.
Put Bog Ravine on top of your library: Add to your mana pool.
: Bog Ravine becomes a 2/1 black and red Zombie creature until end of turn. It's still a land.
.
: Add or 
to your mana pool.
to your mana pool. : Bog Ravine becomes a 2/1 black and red Zombie creature until end of turn. It's still a land.
