Autumn Willow of Great Wood

Whenever another creature enters the battlefield,
that creatures controller gains life equal to its toughness.
Whenever a player taps a land for mana,
that player adds one mana of any type that land produced.
{2}{g}{g}{t}: Create 6/2 green Elemental creature
token named Hungry Mist with "At the beginning
of your upkeep, sacrifice Hungry Mist unless you
pay {g}{g}"