Invasion of Eldraine // Prickle Faeries (MOM-113) - March of the Machine

(As a Siege enters, choose an opponent to protect it. You and others can attack it. When it's defeated, exile it, then cast it transformed.)
When Invasion of Eldraine enters the battlefield, target opponent discards two cards.

Flying
At the beginning of each opponent's upkeep, if that player has two or fewer cards in hand, Prickle Faeries deals 2 damage to them.