Nightcap Undergrowth

Whenever a creature you control dies, add {g}{b} to your mana pool.
{t}: Add {g} or {b} to your mana pool.
{1}{g}{b},{t}, Sacrifice Nightcap Undergrowth: Create a 1/1 green and black Myconid creature token, for each creature, in all graveyards.

Nature efficiently disposes of the deceased.