Viral Spawning (ONE) from Phyrexia: All Will Be One, available at 401 Games Canada.

• Rarity: Uncommon
• Finish: Normal
• Artist: Denis Zhbankov
• Card Text:
  Create a 3/3 green Phyrexian Beast creature token with toxic 1. (Players dealt combat damage by it also get a poison counter.)
  Corrupted — As long as an opponent has three or more poison counters and Viral Spawning is in your graveyard, it has flashback 2G. (You may cast this card from your graveyard for its flashback cost. Then exile it.)