The Nature's Gateway

I, II: Put the top two cards of you library into
your graveyard, then add {g} for each land card
put into your graveyard this way. Until end of
turn, this mana doesn't empty from your mana
pool as steps and phases end.
III: Search your library for a green creature
card with converted mana cost X or less, where X
is the number of land cards in your graveyard,
put it onto the battlefield, then shuffle your
library.