Hollow Chamber enters the battlefield tapped.
, : Add to your mana pool.
: Hollow Chamber becomes a 1/1 blue and black Rat creature with flying until end of turn. It's still a land.
, 
: Add 
to your mana pool., : Add to your mana pool.
: Hollow Chamber becomes a 1/1 blue and black Rat creature with flying until end of turn. It's still a land.
