Vannifar, Evolved Enigma is a mythic Legendary Creature — Elf Ooze Wizard card from Murders at Karlov Manor (MKM), collector number 241. Current market price: $0.42 (foil $0.96), TCGplayer market prices via Scryfall.
At the beginning of combat on your turn, choose one — • Cloak a card from your hand. (Put it onto the battlefield face down as a 2/2 creature with ward {2}. Turn it face up any time for its mana cost if it's a creature card.) • Put a +1/+1 counter on each colorless creature you control.