"I can prove I won fair and square—I have the receipt."

Secret Lair Drop

Revel in Riches

Whenever a creature an opponent controls dies, create a Treasure token. (It's an artifact with "{T}, Sacrifice this token: Add one mana of any color.")
At the beginning of your upkeep, if you control ten or more Treasures, you win the game.

The List

Ixalan Promos

Ixalan

Whenever a creature an opponent controls dies, create a colorless Treasure artifact token with "{T}, Sacrifice this artifact: Add one mana of any color to your mana pool."
At the beginning of your upkeep, if you control ten or more Treasures, you win the game.