Is Slipstream Serpent legal in Standard, Modern, and Commander?

Slipstream Serpent is legal in: Modern, Legacy, Vintage, Commander, Pauper.

Slipstream Serpent

Q: What type of card is Slipstream Serpent?

Slipstream Serpent is a Creature — Serpent. Its oracle text reads: "This creature can't attack unless defending player controls an Island. When you control no Islands, sacrifice this creature. Morph {5}{U} (You may cast this card face down as a 2/2 creature for {3}. Turn it face up any time for its morph cost.)"