Hollow Valley enters the battlefield tapped.
: Add or to your mana pool.
Sacrifice Hollow Valley: Add or to your mana pool.
: Hollow Valley becomes a 2/1 black and green Wizard Cleric creature until end of turn. It's still a land.
: Add 
or 
to your mana pool. or to your mana pool.: Hollow Valley becomes a 2/1 black and green Wizard Cleric creature until end of turn. It's still a land.
