Hyrm, The Forest Sage

Green Mana doesn't empty from your pool as
steps and phases end.
{t}, add {g}{g} to your Mana
Landfall, whenever land you control enters the battlefield put a +1/+1
counter on creatures you control
{5}{g}{t}, Turn a land into a 6/6 green treefolk
token with trample, it's still a land