Vraska, Betrayal's Sting [Phyrexia: All Will Be One Prerelease Promos] Bird Illusion Set: March of the Machine:

Set: March of the Machine: The Aftermath Type: Legendary Artifact Creature — Golem Rarity: Mythic Cost: {5} Karn

Every branch a crossroads

Whenever another creature enters the battlefield under your control

If they're put on a player this way

Vraska, Betrayal's Sting [Phyrexia: All Will Be One Prerelease Promos] Bird Illusion Set: March of the Machine:Set: Phyrexia: All Will Be One Prerelease Promos Type: Legendary Planeswalker Vraska Rarity: Mythic Cost: {4}{B}{B P} Compleated ({B P} can be paid with {B}, or 2 life. If life was paid, this planeswalker enters with two fewer loyalty counters.) 0: You draw a card and you lose 1 life. Proliferate. 2: Target creature becomes a Treasure artifact with "{T}, Sacrifice this artifact: Add one mana of any color" and loses all other card types and abilities.