Effluence Devourer

Whenever you sacrifice Effluence Devourer or another creature, it perpetually gains "2, Exile this card from your graveyard: Create an X/X green Ooze creature token, where X is this card's power. Activate only as a sorcery."

Blitz BRG (If you cast this spell for its blitz cost, it gains haste and "When this creature dies, draw a card." Sacrifice it at the beginning of the next end step.)