Predatory Sludge 
Creature — Ooze
Menace As Predatory Sludge enters the battlefield, choose a permanent you don't control. When the chosen permanent is put into a graveyard from the battlefield, conjure a card named Predatory Sludge into your hand.
Legality
standardNOT LEGALpioneerNOT LEGALmodernNOT LEGALlegacyNOT LEGALvintageNOT LEGALcommanderNOT LEGAL