One With Life

{g}{g}: One With Life becomes a 7/7 Elemental Creature with defender until end of turn.
{g}{g}: If One With Life is an Elemental, it becomes a 9/9 Giant with trample instead.
{4}: If One With Life has trample, you may sacrifice it. If you do, target player gains 5 life and 1 life for every Forest you control.