Is Master of Pearls legal in Standard, Modern, and Commander?

Master of Pearls is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

What type of card is Master of Pearls?

Master of Pearls is a Creature — Human Monk. Its oracle text reads: "Morph {3}{W}{W} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.) When this creature is turned face up, creatures you control get +2/+2 until end of turn."