Is Skinthinner legal in Standard, Modern, and Commander?

Skinthinner is legal in: Legacy, Vintage, Commander, Pauper.

What type of card is Skinthinner?

Skinthinner is a Creature — Zombie. Its oracle text reads: "Morph {3}{B}{B} (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, destroy target nonblack creature. It can't be regenerated."