Salt Road Ambushers is a uncommon Creature — Dog Warrior card from Murders at Karlov Manor Commander (MKC), collector number 184. Current market price: $0.31, TCGplayer market prices via Scryfall.
Whenever another permanent you control is turned face up, if it's a creature, put two +1/+1 counters on it. Megamorph {3}{G}{G} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its megamorph cost and put a +1/+1 counter on it.)