Viral Spawning is a uncommon Sorcery card from Phyrexia: All Will Be One (ONE), collector number 194. Current market price: $0.25 (foil $0.22), TCGplayer market prices via Scryfall.
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 this card is in your graveyard, it has flashback {2}{G}. (You may cast this card from your graveyard for its flashback cost. Then exile it.)