River Cavern enters the battlefield tapped.
: Add to your mana pool.
: Add or to your mana pool. Each opponent gains 1 life.
: River Cavern becomes a 2/1 blue and black Fish creature until end of turn. It's still a land.
: Add 
to your mana pool.: Add 
or 
to your mana pool. Each opponent gains 1 life.: River Cavern becomes a 2/1 blue and black Fish creature until end of turn. It's still a land.
