Furgul, Quag Nurturer is a rare Legendary Creature — Elf Shaman card from Alchemy: Murders at Karlov Manor (YMKM), collector number 23.
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.