Is Horde Ambusher legal in Standard, Modern, and Commander?

Horde Ambusher is legal in: Modern, Pioneer, Legacy, Vintage, Commander, Historic.

Horde Ambusher

Q: What type of card is Horde Ambusher?

Horde Ambusher is a Creature — Human Berserker. Its oracle text reads: "Whenever this creature blocks, it deals 1 damage to you. Morph—Reveal a red card in your hand. (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 can't block this turn."