Karlov Watchdog is a uncommon Creature — Dog card from Murders at Karlov Manor (MKM), collector number 20. Current market price: $0.12 (foil $0.19), TCGplayer market prices via Scryfall.
Vigilance Permanents your opponents control can't be turned face up during your turn. Whenever you attack with three or more creatures, creatures you control get +1/+1 until end of turn.