Sporogenesis | Magic: The Gathering
Formats Sporogenesis is Legal in
Official Oracle Text for Sporogenesis
Whenever a creature with a fungus counter on it dies, put a 1/1 green Saproling creature token onto the battlefield for each fungus counter on that creature.
When Sporogenesis leaves the battlefield, remove all fungus counters from all creatures.
Official Rulings for Sporogenesis
10/4/2004 : If more than one Sporogenesis is on the battlefield and a creature with fungus counters on it leaves the battlefield, each Sporogenesis will put a Saproling onto the battlefield for each counter. In other words if there are N copies of Sporogenesis and the creature had M fungus counters, you get N * M Saprolings.
10/4/2004 : If one Sporogenesis leaves the battlefield, all fungus counters are removed even if other Sporogenesis cards are on the battlefield.
10/4/2004 : Adding a counter is optional. If you forget to add one during your upkeep, you cannot back up and add one later.