Is Icewrought Sentry legal in Standard, Modern, and Commander?

Icewrought Sentry is legal in: Standard, Modern, Pioneer, Legacy, Vintage, Commander, Historic.

What type of card is Icewrought Sentry?

Icewrought Sentry is a Creature — Elemental Soldier. Its oracle text reads: "Vigilance Whenever this creature attacks, you may pay {1}{U}. When you do, tap target creature an opponent controls. Whenever you tap an untapped creature an opponent controls, this creature gets +2/+1 until end of turn. Power/Toughness: 2/3"