The Arbor Queen

(The Arbor Queen isn't a spell, it's affected by
summoning sickness, and it has "{t}: Add {g}.")
{u}{b}{g}, {t}: Return target land from a graveyard
to the battlefield under your control. If it is a
forest, it becomes a 0/1 green dryad creature in addition.
Things die, nurture the soil, and the forest lives off the
land, giving shelter to life to continue the cycle.