Katerina of Myra's Marvels is a rare Legendary Creature — Human Performer card from Unfinity (UNF), collector number 245. Current market price: $0.18 (foil $0.26), TCGplayer market prices via Scryfall.
As Katerina of Myra's Marvels enters, choose a letter. Whenever you cast a spell whose name begins with the chosen letter, create a white 2/2 Cat creature token with flying. Partner (You can have two commanders if they both have partner.)