Salt Road Ambushers (198) [Dragons of Tarkir]

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.)