When Krosan Karoo enters the battlefield, return a land you control to its owner's hand.
: Add or to your mana pool.
: Add to your mana pool. Put Krosan Karoo on top of your library.
Sacrifice a Green permanent: You gain 3 life.
: Add 
or 
to your mana pool.: Add 
to your mana pool. Put Krosan Karoo on top of your library.
