Is Patron of the Wild legal in Standard, Modern, and Commander?

Patron of the Wild is legal in: Legacy, Vintage, Commander, Pauper.

What type of card is Patron of the Wild?

Patron of the Wild is a Creature — Elf. Its oracle text reads: "Morph {2}{G} (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, target creature gets +3/+3 until end of turn."