Heart of Llanowar

{3}, {t}: create a 1/1 green elf creature token with:
"{t}: add {g}", then draw a card.
{t}: add {g}{g}. activate this ability only if you
control four or more creatures.
{5}: Until end of turn, Heart of Llanowar
becomes a 1/1 green elf creature with: "{t}:
Double the amount of each type of unspent
mana you have."
Heart of Llanowar can be your commander.