Is Aquus Steed legal in Standard, Modern, and Commander?

Aquus Steed is legal in: Modern, Pioneer, Legacy, Vintage, Commander.

Aquus Steed

Q: What type of card is Aquus Steed?

Aquus Steed is a Creature — Beast. Its oracle text reads: "{2}{U}, {T}: Target creature gets -2/-0 until end of turn. *In water, it's as graceful as a dolphin. On land, it darts and jerks so unpredictably that few can ride it for long.* Power/Toughness: 1/3"