Sporogenesis
Urza's Saga — Rare
Enchantment
Sporogenesis rulings:
2004-10-04: If a non-creature with fungus counters on it leaves the battlefield, there is no effect.
2004-10-04: 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.
2004-10-04: If one Sporogenesis leaves the battlefield, all fungus counters are removed even if other Sporogenesis cards are on the battlefield.
2004-10-04: Adding a counter is optional. If you forget to add one during your upkeep, you cannot back up and add one later.