Water Gun Balloon Game is a rare Artifact card from Unsanctioned (UND), collector number 85. Current market price: $0.18, TCGplayer market prices via Scryfall.
As this artifact enters, each player puts a pop! counter on "0." Whenever a player casts a spell, move that player's pop! counter up one. Whenever a player's pop! counter hits "5," that player creates a 5/5 pink Giant Teddy Bear creature token and resets all pop! counters to "0."