Envoy of Gluttony

(Transforms from Curse of Gluttony)
Trample
At the beginning of your upkeep, sacrifice a land. Whenever a land is put into a graveyard from anywhere, put two +1/+1 counters of Envoy of Gluttony.
Whenever a creature you control deals combat
damage to a player, add X mana of any color to
your mana pool, where X is the combat damage
dealt. This mana doesn't empty from your
mana pool.