Caves Plain enters the battlefield tapped.
: Add or to your mana pool.
Sacrifice Caves Plain: Add or to your mana pool.
: Caves Plain becomes a 2/1 black and white Rat creature until end of turn. It's still a land.
: Add 
or 
to your mana pool. or to your mana pool.: Caves Plain becomes a 2/1 black and white Rat creature until end of turn. It's still a land.
