Fungal Mulch

{t}: Add {c} to your mana pool.
{t}: Exile two target cards in a single graveyard.
If you do, add {b} or {g} to your mana pool.
{t}: Exile three target cards in a single graveyard. If you do, add one mana of any color to your
mana pool.
They are fed by dying memories of ancient gods.