Arid Tubes enters the battlefield tapped.
, : Add , or to your mana pool.
: Arid Tubes becomes a 2/1 white and black Knight creature until end of turn. It's still a land.
, 
: Add 
, 
or to your mana pool.: Arid Tubes becomes a 2/1 white and black Knight creature until end of turn. It's still a land.
