Sporogenesis (USG) from Urza's Saga, available at 401 Games Canada.

• Rarity: Rare
• Finish: Normal
• Artist: Ron Spencer
• Card Text:
  During your upkeep, you may put a fungus counter on target nontoken creature.
  Whenever a creature with a fungus counter on it is put into a graveyard, put a Saproling token into play for each of those fungus counters. Treat these tokens as 1/1 green creatures.
  When Sporogenesis leaves play, remove all fungus counters from all creatures.