Forum Familiar is a uncommon Creature — Cat card from Murders at Karlov Manor (MKM), collector number 16. Current market price: $0.09 (foil $0.18), TCGplayer market prices via Scryfall.
Disguise {1}{W} (You may cast this card face down for {3} as a 2/2 creature with ward {2}. Turn it face up any time for its disguise cost.) When this creature is turned face up, return another target permanent you control to its owner's hand and put a +1/+1 counter on this creature.