Furgul, Quag Nurturer

Legendary Creature — Elf Shaman — {2}{B}{G}

At the beginning of your end step, conjure a card named Slimy Dualleech onto the battlefield if you control no Leeches. Otherwise, put a +1/+1 counter on each Leech you control. {T}, Sacrifice a creature: Add an amount of {G} equal to the sacrificed creature's power.